甜菜碱醛脱氢酶BADH、紫花苜蓿、盐胁迫、逆境
BADH—甜菜碱(GB)合成及盐胁迫响应的通用机制与改良综述
这组文献以综述/机制框架为主,聚焦BADH在甜菜碱(GB)合成中的关键作用,以及GB通过渗透调节、ROS清除、膜/蛋白保护等参与盐胁迫等多种逆境;同时讨论BADH相关信号途径(如MAPK)、与其他基因/策略的协同,以及在作物改良中的应用路径与前景。
- Critical multifunctional role of the betaine aldehyde dehydrogenase gene in plants(F. S. Golestan Hashemi, M. Ismail, M. Rafii, F. Aslani, G. Miah, F. M. Muharam, 2018, Biotechnology & Biotechnological Equipment)
- Advances in the Biosynthetic Regulation and Functional Mechanisms of Glycine Betaine for Enhancing Plant Stress Resilience(Jiaxu Chen, Jing Zhang, Yihang Liu, Kailu Zhang, Fuyuan Zhu, Yanjie Xie, 2025, International Journal of Molecular Sciences)
- Glycine Betaine is a Phytohormone-Like Plant Growth and Development Regulator Under Stress Conditions(Sergio G. Hernandez-Leon, E. Valenzuela-Soto, 2022, Journal of Plant Growth Regulation)
- Betaine Aldehyde Dehydrogenase (BADH) vs. Flavodoxin (Fld): Two Important Genes for Enhancing Plants Stress Tolerance and Productivity(M. Niazian, S. Sadat-Noori, M. Tohidfar, Seyed Mohammad Mehdi Mortazavian, P. Sabbatini, 2021, Frontiers in Plant Science)
- Molecular Approaches to Improve Legume Salt Stress Tolerance(A. El Moukhtari, N. Lamsaadi, Cécile Cabassa, M. Farissi, A. Savouré, 2024, Plant Molecular Biology Reporter)
BADH/ALDH基因工程改造与盐胁迫耐受的功能验证(含转基因与共转化)
这组文献提供了“功能层面”的证据:通过BADH/ALDH家族相关基因转化或异源表达(或与其他耐受基因共转化)来验证其是否能提升/调控盐胁迫耐受,并配套观察生理指标、离子稳态、光合保护或代谢/蛋白响应结果。其中含有紫花苜蓿转基因的直接证据及BADH与相关基因家族在耐受中的作用讨论。
- Enhancement of salt tolerance in alfalfa transformed with the gene encoding for betaine aldehyde dehydrogenase(Zihui Liu, Hong-Mei Zhang, Guo-liang Li, Xiulin Guo, S. Chen, Guizhen Liu, Yan-min Zhang, 2011, Euphytica)
- Physiological responses to salt stress of T2 alfalfa progenies carrying a transgene for betaine aldehyde dehydrogenase(Liping Yan, Cuilan Liu, Huimin Liang, Xiuhong Mao, Fei Wang, Caihong Pang, Jing Shu, Yang Xia, 2011, Plant Cell, Tissue and Organ Culture (PCTOC))
- A novel betaine aldehyde dehydrogenase gene from Medicago sativa and its expression under salinity.(L. Amjad, H. Nosrati, F. Zaare, G. Dehghan, M. Husainpourfazi, S. Salehi, 2015, The Journal "Agriculture and Forestry")
- A betaine aldehyde dehydrogenase gene from Ammopiptanthus nanus enhances tolerance of Arabidopsis to high salt and drought stresses(Haoqiang Yu, Xia-Yu Zhou, Yingge Wang, Shufeng Zhou, F. Fu, Wanchen Li, 2017, Plant Growth Regulation)
- Expression of Beta vulgaris betaine aldehyde dehydrogenase 1 (BvBADH1) confers salt tolerance in tobacco (Nicotiana benthamiana)(Ming Wei, Xiangping Chen, Meng-Li Li, Hao Li, Xinrui Wu, Guo-Qiang Wu, 2025, Physiology and Molecular Biology of Plants)
- A proteomic approach to understand the impact of nodulation on salinity stress response in alfalfa (Medicago sativa L.).(Y. Wang, P. Yang, Y. Zhou, T. Hu, P. Zhang, Y. Wu, 2021, Plant Biology)
- Co-transforming bar and CsALDH Genes Enhanced Resistance to Herbicide and Drought and Salt Stress in Transgenic Alfalfa (Medicago sativa L.)(Z. Duan, Daiyu Zhang, Jianquan Zhang, Hongyan Di, Fan Wu, Xiaowen Hu, Xuanchen Meng, Kai Luo, Jiyu Zhang, Yanrong Wang, 2015, Frontiers in Plant Science)
紫花苜蓿盐胁迫/盐碱复合逆境的组学与代谢响应解析(转录组/蛋白组/代谢组/整合组学)
这组文献共同点是以紫花苜蓿在盐胁迫(含盐碱、长期盐处理等逆境)下的分子响应为主线,采用高通量组学(转录组、蛋白组、代谢组或整合多组学)解析差异基因/蛋白/代谢物及其富集通路(如光合作用、糖代谢、花青素/苯丙烷代谢、谷胱甘肽/抗氧化、碳固定等),并与生理表型变化相互印证。
- Comparative transcriptomic and proteomic analyses of two salt-tolerant alfalfa (Medicago sativa L.) genotypes: investigation of the mechanisms underlying tolerance to salt(Jiahui Hang, Ting Song, Ling Zhang, Wenjun Hou, Xiaoxia Liu, Dongmei Ma, 2024, Frontiers in Plant Science)
- Metabolo‐Transcriptomics Analyses Reveal Alfalfa Adaptation to Combined Saline‐Alkali and Low‐Temperature Stress in the Field(Rui Guo, Lei Liu, Jiaqi Li, Hongyu Qu, Weileng Guo, Lishuang Zhang, Dihe Yang, Ruixin Wang, Changhong Guo, 2025, Plant Biotechnology Journal)
- Metabolomic and physiological analysis of alfalfa (Medicago sativa L.) in response to saline and alkaline stress.(Rui Guo, Zeyu Zhou, Run Cai, Lei Liu, Ruixin Wang, Yugang Sun, Dan Wang, Zhe Yan, Changhong Guo, 2024, Plant Physiology and Biochemistry)
- Transcriptomic Analysis Identifies Molecular Response of the Tolerant Alfalfa (Medicago sativa) Cultivar Nongjing 1 to Saline-Alkali Stress(Dongmei Zhang, Jinxia Li, Yiming Zhang, Yuanhao Zhang, Wenhui Wang, Zhaohui Li, Peng Zhu, Yongshun Huang, Long Han, Mingyu Wang, Zijian Zhang, Zhongbao Shen, Weibo Han, Linlin Mou, Zhuang Xu, Qiuying Pang, Jianli Wang, Lixin Li, 2025, Biology)
- Unveiling Salt Tolerance Mechanisms and Hub Genes in Alfalfa (Medicago sativa L.) Through Transcriptomic and WGCNA Analysis(Fengdan Wang, Hanfu Wu, Mei Yang, Wen Xu, Wenjie Zhao, Rui Qiu, Ning Kang, Guowen Cui, 2024, Plants)
- Elucidation of Physiological, Transcriptomic and Metabolomic Salinity Response Mechanisms in Medicago sativa(S. Singer, Madeline Lehmann, Zixuan Zhang, U. Subedi, Kimberley Burton Hughes, Nathaniel Z-L Lim, R. Ortega Polo, Guanqun Chen, S. Acharya, A. Hannoufa, T. Huan, 2023, Plants)
- A proteomic approach to understand the impact of nodulation on salinity stress response in alfalfa (Medicago sativa L.).(Y. Wang, P. Yang, Y. Zhou, T. Hu, P. Zhang, Y. Wu, 2021, Plant Biology)
紫花苜蓿盐胁迫的遗传关联与育种指标体系(GWAS/位点与综合表型)
这组文献以“遗传基础与可育种性证据”为核心:通过GWAS或表型综合评估获得与盐胁迫相关的位点/候选基因/关键表型变量,并给出与转录组结果或盐胁迫耐受分类相关的线索,用于分子育种与标记辅助选择。
- Genome-Wide Association Analysis Coupled With Transcriptome Analysis Reveals Candidate Genes Related to Salt Stress in Alfalfa (Medicago sativa L.)(F. He, Chunxue Wei, Yunxiu Zhang, R. Long, Mingna Li, Zhen Wang, Qingchuan Yang, Junmei Kang, Lin Chen, 2022, Frontiers in Plant Science)
- Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicago sativa L.) Using Genotyping-by-Sequencing(Long-Xi Yu, Xinchun Liu, W. Boge, Xiang Liu, 2016, Frontiers in Plant Science)
- Comprehensive evaluation of physio‐morphological traits of alfalfa (Medicago sativa L.) varieties under salt stress(Yuxi Feng, Zhao Chen, Luyun Chen, Mengli Han, Jiayi Liu, Yichun Liu, Rundong Chai, Jiamin Wang, Shengnan Sun, Jibiao Fan, Xuebing Yan, Yuxia Guo, 2025, Physiologia Plantarum)
ALDH/BADH家族的进化与跨物种机制补充(家族功能、进化路径与特征分析)
该组文献用于从“机制框架补充与跨物种拓展”角度理解ALDH/BADH体系:包括ALDH家族在非盐条件(碱性等)或不同逆境中对毒性醛代谢清除的响应、家族进化与BADH/BAL底物特异性的演化路径,以及某些基因在组织特异性与盐胁迫诱导中的特征总结。整体上为理解BADH/ALDH在逆境耐受中的系统性提供理论与进化背景。
- Effects, tolerance mechanisms and management of salt stress in lucerne (Medicago sativa)(S. Al-Farsi, A. Nawaz, .. Anees-ur-Rehman, S. Nadaf, A. Al‐Sadi, K. Siddique, M. Farooq, 2020, Crop & Pasture Science)
- Comprehensive analysis of the aldehyde dehydrogenase gene family in Phaseolus vulgaris L. and their response to saline–alkali stress(Xiaoqin Wang, Mingxu Wu, Song Yu, Lingxia Zhai, Xue-Ping Zhu, Lihe Yu, Yifei Zhang, 2024, Frontiers in Plant Science)
- Exploring the evolutionary route of the acquisition of betaine aldehyde dehydrogenase activity by plant ALDH10 enzymes: implications for the synthesis of the osmoprotectant glycine betaine(R. Muñoz-Clares, Héctor Riveros-Rosas, G. Garza-Ramos, L. González‐Segura, C. Mújica-Jiménez, Adriana Julián‐Sánchez, 2014, BMC Plant Biology)
- Identification, characterization, and evolutionary analysis of aldehyde dehydrogenase (ALDH) genes superfamily in Medicago truncatula L(S. Allahi, Amin Abedi, H. H. Kumleh, M. Sohani, 2025, Genetica)
围绕“BADH/甜菜碱代谢—紫花苜蓿—盐胁迫/复合逆境”的研究,文献可概括为:①BADH及其在甜菜碱(GB)合成与逆境适应中的机制与进化;②BADH基因/甜菜碱代谢的遗传改造或功能证据(含对盐胁迫耐受的转基因验证与相关综述);③紫花苜蓿在盐胁迫或盐碱复合逆境下的组学与代谢表型解析(转录组/蛋白组/代谢组/整合组学);④紫花苜蓿在盐胁迫下的遗传基础与分子育种线索(GWAS/QTL/候选基因、WGCNA枢纽基因等);⑤更广义的盐胁迫生理-代谢响应与综合管理策略(含综述、跨物种/路径证据,用于机制框架补充)。
总计26篇相关文献
… In the present study Medicago sativa cv. Gara-Yonjeh growth was significantly inhibited by salt stress at … Our results suggest that BADH play no important role on salinity tolerance in M. …
… BADH was transformed into alfalfa (Medicago sativa L.) through Agrobacterium-mediated transformation method, and salt tolerance … using the primers specific for BADH gene. Reverse …
… In this study, a BADH gene was over expressed in transgenic alfalfa (Medicago sativa L) plants using Agrobacterium-mediated transformation. Transgenic alfalfa plants grown under 9‰ …
… salt stress became increasingly significant, especially in the context of meeting the rising demands of a growing world population. This review focuses on the impact of salt stress … BADH …
Alfalfa (Medicago sativa L.) is a widely grown perennial leguminous forage crop with a number of positive attributes. However, despite its moderate ability to tolerate saline soils, which are increasing in prevalence worldwide, it suffers considerable yield declines under these growth conditions. While a general framework of the cascade of events involved in plant salinity response has been unraveled in recent years, many gaps remain in our understanding of the precise molecular mechanisms involved in this process, particularly in non-model yet economically important species such as alfalfa. Therefore, as a means of further elucidating salinity response mechanisms in this species, we carried out in-depth physiological assessments of M. sativa cv. Beaver, as well as transcriptomic and untargeted metabolomic evaluations of leaf tissues, following extended exposure to salinity (grown for 3–4 weeks under saline treatment) and control conditions. In addition to the substantial growth and photosynthetic reductions observed under salinity treatment, we identified 1233 significant differentially expressed genes between growth conditions, as well as 60 annotated differentially accumulated metabolites. Taken together, our results suggest that changes to cell membranes and walls, cuticular and/or epicuticular waxes, osmoprotectant levels, antioxidant-related metabolic pathways, and the expression of genes encoding ion transporters, protective proteins, and transcription factors are likely involved in alfalfa’s salinity response process. Although some of these alterations may contribute to alfalfa’s modest salinity resilience, it is feasible that several may be disadvantageous in this context and could therefore provide valuable targets for the further improvement of tolerance to this stress in the future.
Abiotic stressors such as salt stress restrict plant development and output, which lowers agricultural profitability. In this study, alfalfa (Medicago sativa L.) varieties with different levels of salt tolerance were examined using high-throughput RNA sequencing (RNA-Seq) and Tandem Mass Tags (TMT) technologies to study the reactions of the root systems to salt stress, from transcriptomics and proteomics perspectives. The varieties Atlantic (AT) and Zhongmu-1 (ZM-1) were selected and evaluated after 2 h and 6 h of treatment with 150 mM NaCl. The results showed that under salt stress for 2 h, 1810 differentially expressed genes (DEGs) and 160 differentially expressed proteins (DEPs) in AT were screened, while 9341 DEGs and 193 DEPs were screened in ZM-1. Under salt stress for 6 h, 7536 DEGs and 118 DEPs were screened in AT, while 11,754 DEGs and 190 DEPs were screened in ZM-1. Functional annotation and pathway enrichment analyses indicated that the DEGS and DEPs were mainly involved in the glutathione metabolism, biosynthesis of secondary metabolites, glycolysis/gluconeogenesis, carbon fixation in photosynthetic organisms, and photosynthesis pathways. A series of genes related to salt tolerance were also identified, including GSTL3 and GSTU3 of the GST gene family, PER5 and PER10, of the PER gene family, and proteins such as APR and COMT, which are involved in biosynthesis of secondary metabolites. This study provides insights into salt resistance mechanisms in plants, and the related genes and metabolic pathways identified may be helpful for alfalfa breeding in the future.
Drought and high salinity are two major abiotic factors that restrict the productivity of alfalfa. By application of the Agrobacterium-mediated transformation method, an oxidative responsive gene, CsALDH12A1, from the desert grass Cleistogenes songorica together with the bar gene associated with herbicide resistance, were co-transformed into alfalfa (Medicago sativa L.). From the all 90 transformants, 16 were positive as screened by spraying 1 mL L-1 10% Basta solution and molecularly diagnosis using PCR. Real-time PCR analysis indicated that drought and salt stress induced high CsALDH expression in the leaves of the transgenic plants. The CsALDH expression levels under drought (15 d) and salt stress (200 mM NaCl) were 6.11 and 6.87 times higher than in the control plants, respectively. In comparison to the WT plants, no abnormal phenotypes were observed among the transgenic plants, which showed significant enhancement of tolerance to 15 d of drought and 10 d of salinity treatment. Evaluation of the physiological and biochemical indices during drought and salt stress of the transgenic plants revealed relatively lower Na+ content and higher K+ content in the leaves relative to the WT plants, a reduction of toxic on effects and maintenance of osmotic adjustment. In addition, the transgenic plants could maintain a higher relative water content level, higher shoot biomass, fewer changes in the photosystem, decreased membrane injury, and a lower level of osmotic stress. These results indicate that the co-expression of the introduced bar and CsALDH genes enhanced the herbicide, drought and salt tolerance of alfalfa and therefore can potentially be used as a novel genetic resource for the future breeding programs to develop new cultivars.
Alfalfa (Medicago sativa L.), an important forage crop with high nutritional value and good palatability, plays a vital role in the development of animal husbandry in China. In Northeast China, there are vast areas of saline–alkali land that remain undeveloped. Given that alfalfa is a highly adaptable forage crop, exploring its salt tolerance at the molecular transcriptional level and identifying salt-tolerant genes has great significance for breeding salt-resistant alfalfa varieties. This also provides valuable genetic resources for better utilization of saline–alkali land. In this study, we conducted two rounds of screening on 41 alfalfa varieties and identified WL168 as a salt-sensitive variety and Longmu801 as a salt-tolerant variety. After 7 days of 300 mM salt stress, both varieties showed a decreasing trend in plant height, fresh weight, and dry weight over time, but Longmu801 demonstrated better water retention ability compared to WL168. Chlorophyll content also declined, but chlorophyll a and total chlorophyll levels in Longmu801 were higher than in WL168. Hydrogen peroxide and malondialdehyde levels increased overall, but Longmu801 had significantly lower levels than WL168 under prolonged stress. Both varieties showed increasing trends in soluble sugars, proline, and antioxidant enzymes (SOD, POD, CAT), with Longmu801 significantly outperforming WL168. This suggests that the two varieties share similar growth and physiological response mechanisms, with their differences primarily arising from variations in indicator levels. In the above, comparisons between varieties were conducted based on the relative values of the indicators in relation to their controls. Transcriptomic analysis revealed that under salt stress, Longmu801 had 16,485 differentially expressed genes (DEGs) relative to its control, while WL168 had 18,726 DEGs compared to its control. Among these, 2164 DEGs shared the same expression trend, with GO functions enriched in response to oxidative stress, nucleus, plasma membrane, and others. The KEGG pathways were enriched in phenylpropanoid biosynthesis, protein processing in the endoplasmic reticulum, starch and sucrose metabolism, and others. This suggests that alfalfa’s transcriptional response mechanism to salt stress involves these pathways. Additionally, the variety-specific DEGs were also enriched in the same KEGG pathways and GO functions, indicating that the differences between the two varieties stem from their unique stress-responsive DEGs, while their overall mechanisms for coping with stress remain similar. To further identify salt stress-related genes, this study conducted WGCNA analysis using 32,683 genes and physiological indicators. Six modules closely related to physiological traits were identified, and the top five genes ranked by degree in each module were selected as hub genes. Further analysis of these hub genes identified five genes directly related to salt stress: Msa085011, Msa0605650, Msa0397400, Msa1258740, and Msa0958830. Mantel test analysis revealed that these genes showed strong correlations with physiological indicators. This study will provide important insights for breeding salt-tolerant alfalfa varieties.
Salt stress is the main abiotic factor affecting alfalfa yield and quality. However, knowledge of the genetic basis of the salt stress response in alfalfa is still limited. Here, a genome-wide association study (GWAS) involving 875,023 single-nucleotide polymorphisms (SNPs) was conducted on 220 alfalfa varieties under both normal and salt-stress conditions. Phenotypic analysis showed that breeding status and geographical origin play important roles in the alfalfa salt stress response. For germination ability under salt stress, a total of 15 significant SNPs explaining 9%–14% of the phenotypic variation were identified. For tolerance to salt stress in the seedling stage, a total of 18 significant SNPs explaining 12%–23% of the phenotypic variation were identified. Transcriptome analysis revealed 2,097 and 812 differentially expressed genes (DEGs) that were upregulated and 2,445 and 928 DEGs that were downregulated in the leaves and roots, respectively, under salt stress. Among these DEGs, many encoding transcription factors (TFs) were found, including MYB-, CBF-, NAC-, and bZIP-encoding genes. Combining the results of our GWAS analysis and transcriptome analysis, we identified a total of eight candidate genes (five candidate genes for tolerance to salt stress and three candidate genes for germination ability under salt stress). Two SNPs located within the upstream region of MsAUX28, which encodes an auxin response protein, were significantly associated with tolerance to salt stress. The two significant SNPs within the upstream region of MsAUX28 existed as three different haplotypes in this panel. Hap 1 (G/G, A/A) was under selection in the alfalfa domestication and improvement process.
Simple Summary This study investigated the saline-alkali tolerance mechanisms in the tolerant alfalfa cultivar NQ-1 through transcriptomic analysis and metabolite profiling. Under saline-alkali stress, NQ-1 activates key metabolic pathways, including photosynthesis, α-linolenic acid metabolism, and flavonoid biosynthesis, which enhance its stress tolerance. Specific flavonoids and transcription factors potentially involved in regulating these pathways were identified. These findings advance our understanding of stress resistance mechanisms and could serve as a basis for the molecular design breeding of saline-alkali-tolerant alfalfa.
Alfalfa (Medicago sativa L.) is known as the ‘King of Forage’ because of its high protein content and excellent palatability. Alfalfa productivity is adversely affected in cold regions with saline‐alkali soils. However, the mechanisms underlying the response of alfalfa to combined saline‐alkali and low‐temperature stress under field conditions remain unknown. The resistance of two alfalfa cultivars (resistant, ZD; sensitive, BM) in saline‐alkali soil during cold and freezing periods was investigated using transcriptomic and metabolomic analyses. Metabolomic analysis revealed specific accumulation of amino acids, organic acids, carbohydrates, fatty acids and flavonoids in ZD compared with that in BM. The core differential metabolites associated with ZD stress resistance included isoleucine, fumaric acid, raffinose, 2‐hydroxydocosanoic acid and isovitexin. Transcriptomic analysis revealed that ZD enriched more upregulated differentially expressed genes in galactose, starch and sucrose metabolism and flavonoid biosynthesis pathways than BM. Integrated metabolo‐transcriptomic analysis highlighted flavonoid, carbohydrate, glutathione and salicylic acid biosynthesis as key pathways in alfalfa stress response. WGCNA identified 10 hub genes responsive to combined stress, with MsBAM1 potentially regulating the carbohydrate synthesis pathway and its silencing impaired alfalfa resistance to combined saline‐alkali and low‐temperature stress.
Alfalfa (Medicago sativa L.) is a leguminous forage widely grown worldwide. Saline and alkaline stress can affect its development and yield. To elucidate the physiological mechanisms of alfalfa in response to saline and alkaline stress, we investigated the growth and physiological and metabolomic changes in alfalfa under saline (100 mM NaCl) and alkaline (100 mM Na2CO3, NaHCO3) stress. At the same Na+ concentration, alkaline stress caused more damage than that caused by saline stress. A total of 65 and 124 metabolites were identified in response to saline and alkaline stress, respectively. Determination of gene expression, enzyme activity, substance content, and KEGG enrichment analysis in key pathways revealed that alfalfa responded to saline stress primarily by osmoregulation and TCA cycle enhancement. Flavonoid synthesis, TCA cycle, glutamate anabolism, jasmonate synthesis, and cell wall component synthesis increased as responses to alkaline stress. This study provides important resources for breeding saline-alkaline-resistant alfalfa.
Salinity is one of major abiotic stresses limiting alfalfa (Medicago sativa L.) production in the arid and semi-arid regions in US and other counties. In this study, we used a diverse panel of alfalfa accessions previously described by Zhang et al. (2015) to identify molecular markers associated with salt tolerance during germination using genome-wide association study (GWAS) and genotyping-by-sequencing (GBS). Phenotyping was done by germinating alfalfa seeds under different levels of salt stress. Phenotypic data of adjusted germination rates and SNP markers generated by GBS were used for marker-trait association. Thirty six markers were significantly associated with salt tolerance in at least one level of salt treatments. Alignment of sequence tags to the Medicago truncatula genome revealed genetic locations of the markers on all chromosomes except chromosome 3. Most significant markers were found on chromosomes 1, 2, and 4. BLAST search using the flanking sequences of significant markers identified 14 putative candidate genes linked to 23 significant markers. Most of them were repeatedly identified in two or three salt treatments. Several loci identified in the present study had similar genetic locations to the reported QTL associated with salt tolerance in M. truncatula. A locus identified on chromosome 6 by this study overlapped with that by drought in our previous study. To our knowledge, this is the first report on mapping loci associated with salt tolerance during germination in autotetraploid alfalfa. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms by which salt and drought stresses affect alfalfa growth. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance to drought and salt stresses.
Abstract. Lucerne (alfalfa, Medicago sativa L.) is a forage legume that is widely cultivated in arid and semi-arid regions of the world. The main aim of this review was to highlight the effects of salt stress on the performance of lucerne and to suggest different tolerance mechanisms and management strategies for improving its yield under salt stress. Salt stress significantly affects seed germination, carbon fixation, light harvesting, biological N2 fixation, mineral uptake and assimilation and dry-matter accumulation in lucerne. Accumulation of osmolytes or compatible solutes such as proline, polyamines, trehalose and soluble sugars confers salt tolerance in lucerne. Maintenance of low Na+ : K+ ratios, antioxidant enzyme activation, and hormonal regulation also help lucerne to withstand salt stress. The screening of diverse genotypes on the basis of germination indices, gas exchange, biomass production, lipid peroxidation and antioxidant enzymes might be useful for breeding salt-tolerant lucerne genotypes. Novel biotechnological tools and functional genomics used to identify salt-conferring genes and quantitative trait loci will help to improve salt tolerance. Use of rhizobial and non-rhizobial plant growth-promoting bacteria, arbuscular mycorrhizal fungi, exogenous application of osmoprotectants, and seed priming with brassinolide, gibberellic acid and salicylic acid may help to improve lucerne performance in saline environments.
Salt is a major abiotic factor significantly affecting plant growth and development. Alfalfa (Medicago sativa L.), a crucial perennial crop for livestock feed, shows significant differences in salt tolerance among different varieties. This study aimed to comprehensively evaluate the salt tolerance of 30 varieties of alfalfa under salt stress (0, 150, and 300 mmol L−1 NaCl). It showed that shoot height (SH), root length (RL), shoot fresh weight (SFW), and root fresh weight (RFW) were decreased by 37.68%, 35.83%, 43.79% and 48.86%, respectively, under high salt stress. Photosynthesis‐related parameters, including chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (TChl), and carotenoids (Car) contents of all varieties were decreased by 50.13%, 43.73%, 48.17% and 60.86%, respectively, and minimum inhibition of photosynthetic pigment contents was observed in the variety Salsa. The changes of antioxidant enzymes in different alfalfa varieties were also found under salt stress. For example, the APX of Sardi 7 decreased by 641.84%, while the APX of Phabulous decreased by 88.33% compared to the non‐treated controls. Principal component analysis (PCA) identified five major variables: Car, TChl, APX, Chl a, and POD. Finally, each variety's comprehensive tolerance membership function values were calculated by the membership function method, and the 30 varieties were classified into four categories by cluster analysis. Our findings indicate that Sardi 7, Salsa, Gannong No.8, Daye, and Instinct are alfalfa salt‐tolerant varieties. Our study provided baseline information on the response of alfalfa varieties to different salinity levels, which will help select or breed salt‐tolerant varieties.
Abiotic stresses, mainly salinity and drought, are the most important environmental threats that constrain worldwide food security by hampering plant growth and productivity. Plants cope with the adverse effects of these stresses by implementing a series of morpho-physio-biochemical adaptation mechanisms. Accumulating effective osmo-protectants, such as proline and glycine betaine (GB), is one of the important plant stress tolerance strategies. These osmolytes can trigger plant stress tolerance mechanisms, which include stress signal transduction, activating resistance genes, increasing levels of enzymatic and non-enzymatic antioxidants, protecting cell osmotic pressure, enhancing cell membrane integrity, as well as protecting their photosynthetic apparatus, especially the photosystem II (PSII) complex. Genetic engineering, as one of the most important plant biotechnology methods, helps to expedite the development of stress-tolerant plants by introducing the key tolerance genes involved in the biosynthetic pathways of osmolytes into plants. Betaine aldehyde dehydrogenase (BADH) is one of the important genes involved in the biosynthetic pathway of GB, and its introduction has led to an increased tolerance to a variety of abiotic stresses in different plant species. Replacing down-regulated ferredoxin at the acceptor side of photosystem I (PSI) with its isofunctional counterpart electron carrier (flavodoxin) is another applicable strategy to strengthen the photosynthetic apparatus of plants under stressful conditions. Heterologous expression of microbially-sourced flavodoxin (Fld) in higher plants compensates for the deficiency of ferredoxin expression and enhances their stress tolerance. BADH and Fld are multifunctional transgenes that increase the stress tolerance of different plant species and maintain their production under stressful situations by protecting and enhancing their photosynthetic apparatus. In addition to increasing stress tolerance, both BADH and Fld genes can improve the productivity, symbiotic performance, and longevity of plants. Because of the multigenic and complex nature of abiotic stresses, the concomitant delivery of BADH and Fld transgenes can lead to more satisfying results in desired plants, as these two genes enhance plant stress tolerance through different mechanisms, and their cumulative effect can be much more beneficial than their individual ones. The importance of BADH and Fld genes in enhancing plant productivity under stress conditions has been discussed in detail in the present review.
… Additionally, some genes display tissue-specific expression and are induced in response to salt stress, suggesting a significant role for these genes in growth processes and stress …
… salt stress than the wild type. By contrast, the AtALDH10A9 gene did not confer abiotic tolerance, although it kept betaine aldehyde dehydrogenase … alfalfa (Medicago truncatula), and …
Plant ALDH10 enzymes are aminoaldehyde dehydrogenases (AMADHs) that oxidize different ω-amino or trimethylammonium aldehydes, but only some of them have betaine aldehyde dehydrogenase (BADH) activity and produce the osmoprotectant glycine betaine (GB). The latter enzymes possess alanine or cysteine at position 441 (numbering of the spinach enzyme, SoBADH), while those ALDH10s that cannot oxidize betaine aldehyde (BAL) have isoleucine at this position. Only the plants that contain A441- or C441-type ALDH10 isoenzymes accumulate GB in response to osmotic stress. In this work we explored the evolutionary history of the acquisition of BAL specificity by plant ALDH10s. We performed extensive phylogenetic analyses and constructed and characterized, kinetically and structurally, four SoBADH variants that simulate the parsimonious intermediates in the evolutionary pathway from I441-type to A441- or C441-type enzymes. All mutants had a correct folding, average thermal stabilities and similar activity with aminopropionaldehyde, but whereas A441S and A441T exhibited significant activity with BAL, A441V and A441F did not. The kinetics of the mutants were consistent with their predicted structural features obtained by modeling, and confirmed the importance of position 441 for BAL specificity. The acquisition of BADH activity could have happened through any of these intermediates without detriment of the original function or protein stability. Phylogenetic studies showed that this event occurred independently several times during angiosperms evolution when an ALDH10 gene duplicate changed the critical Ile residue for Ala or Cys in two consecutive single mutations. ALDH10 isoenzymes frequently group in two clades within a plant family: one includes peroxisomal I441-type, the other peroxisomal and non-peroxisomal I441-, A441- or C441-type. Interestingly, high GB-accumulators plants have non-peroxisomal A441- or C441-type isoenzymes, while low-GB accumulators have the peroxisomal C441-type, suggesting some limitations in the peroxisomal GB synthesis. Our findings shed light on the evolution of the synthesis of GB in plants, a metabolic trait of most ecological and physiological relevance for their tolerance to drought, hypersaline soils and cold. Together, our results are consistent with smooth evolutionary pathways for the acquisition of the BADH function from ancestral I441-type AMADHs, thus explaining the relatively high occurrence of this event.
Background Aldehyde dehydrogenase (ALDH) scavenges toxic aldehyde molecules by catalyzing the oxidation of aldehydes to carboxylic acids. Although ALDH gene family members in various plants have been extensively studied and were found to regulate plant response to abiotic stress, reports on ALDH genes in the common bean (Phaseolus vulgaris L.) are limited. In this study, we aimed to investigate the effects of neutral (NS) and basic alkaline (AS) stresses on growth, physiological and biochemical indices, and ALDH activity, ALDH gene expression of common bean. In addition, We used bioinformatics techniques to analyze the physical and chemical properties, phylogenetic relationships, gene replication, collinearity, cis-acting elements, gene structure, motifs, and protein structural characteristics of PvALDH family members. Results We found that both NS and AS stresses weakened the photosynthetic performance of the leaves, induced oxidative stress, inhibited common bean growth, and enhanced the antioxidative system to scavenge reactive oxygen species. Furthermore, we our findings revealed that ALDH in the common bean actively responds to NS or AS stress by inducing the expression of PvALDH genes. In addition, using the established classification criteria and phylogenetic analysis, 27 PvALDHs were identified in the common bean genome, belonging to 10 ALDH families. The primary expansion mode of PvALDH genes was segmental duplication. Cis-acting elemental analysis showed that PvALDHs were associated with abiotic stress and phytohormonal responses. Gene expression analysis revealed that the PvALDH gene expression was tissue-specific. For instance, PvALDH3F1 and PvALDH3H1 were highly expressed in flower buds and flowers, respectively, whereas PvALDH3H2 and PvALDH2B4 were highly expressed in green mature pods and young pods, respectively. PvALDH22A1 and PvALDH11A2 were highly expressed in leaves and young trifoliates, respectively; PvALDH18B2 and PvALDH18B3 were highly expressed in stems and nodules, respectively; and PvALDH2C2 and PvALDH2C3 were highly expressed in the roots. PvALDHs expression in the roots responded positively to NS–AS stress, and PvALDH2C3, PvALDH5F1, and PvALDH10A1 were significantly (P < 0.05) upregulated in the roots. Conclusion These results indicate that AS stress causes higher levels of oxidative damage than NS stress, resulting in weaker photosynthetic performance and more significant inhibition of common bean growth. The influence of PvALDHs potentially modulates abiotic stress response, particularly in the context of saline–alkali stress. These findings establish a basis for future research into the potential roles of ALDHs in the common bean.
Plants are frequently exposed to a range of abiotic stresses, including drought, salinity, extreme temperatures, and heavy metals, that severely impair their growth and productivity. Among the adaptive mechanisms that plants have evolved, the accumulation of glycine betaine (GB), a naturally occurring, zwitterionic, and chemically stable osmoprotectant, has been widely recognized as a key strategy for stress tolerance. In higher plants, GB is primarily synthesized via the two-step oxidation of choline, catalyzed by choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH). GB contributes to cellular homeostasis by modulating osmotic balance, regulating ion flux, scavenging reactive oxygen species (ROS), enhancing antioxidant defense systems, and stabilizing proteins and membrane structures. Both exogenous application of GB and genetic engineering approaches aimed at enhancing endogenous GB biosynthesis have been shown to significantly improve plant tolerance to a variety of abiotic stresses. In this review, we provide a comprehensive overview of recent advances in the understanding of GB biosynthesis, its regulatory mechanisms, and its multifaceted roles in plant stress responses. We also highlight emerging prospects for leveraging GB-centered strategies to enhance crop resilience in challenging environmental conditions.
ABSTRACT The betaine aldehyde dehydrogenase (BADH) gene plays a multifunctional role in plants. It is an important factor in fragrance production, abiotic stresses and antibiotic-free selection of transgenic plants. Molecular studies have presented a new picture of this critical factor involved in abiotic stress responses via the MAPK (mitogen-activated protein kinase) signalling pathway in numerous plants. Besides BADH, glycine betaine performs an important function in plant tolerance to environmental stresses. The presence of glycine betaine can help maintain the integrity of cell membranes against unexpected environmental stresses. BADH leads to production of glycine betaine through the oxidation of betaine aldehyde. Hence, BADH is considered a key regulator for glycine betaine formation. Consequently, by providing glycine betaine as a chemical interface, there is a critical role of BADH in enhancing the tolerance in an extensive range of plants subjected to different destructive abiotic stresses. The present article reviews the significant multifunctional role of the BADH gene in various plants, and also particularly argues how this important gene plays a responsive function to different destructive abiotic stresses, and its potential use in crop improvement using advanced technologies. Consequently, cloning of more BADH genes, specially from stress-tolerant plants, discovering their responsive signalling roles under environmental stresses, and validating such candidates for their potential are very helpful, and can open new windows to generate new stress-resistant crop cultivars.
… in old leaves, while BADH levels were high in all tissues. Under salinity stress, GB levels increased in … biosynthesis and its effect on physiological, biochemical, molecular, and metabolic …
Symbiotic nitrogen fixation in legumes is an important source of nitrogen supply in sustainable agriculture. Salinity is a key abiotic stress that negatively affects host plant growth, rhizobium-legume symbiosis and nitrogen fixation. This work investigates how the symbiotic relationship impacts plant response to salinity stress. We assayed the physiological changes and the proteome profile of alfalfa plants with active nodules (NA), inactive nodules (NI) or without nodules (NN) when plants were subjected to salinity stress. Our data suggest that NA plants respond to salinity stress through some unique signalling regulations. NA plants showed upregulation of proteins related to cell wall remodelling and reactive oxygen species scavenging, and downregulation of proteins involved in protein synthesis and degradation. The data also show that NA plants, together with NI plants, upregulated proteins involved in photosynthesis, carbon fixation and respiration, anion transport and plant defence against pathogens. The study suggests that the symbiotic relationship gave the host plant a better capacity to adjust key processes, probably to more efficiently use energy and resources, deal with oxidative stress, and maintain ion homeostasis and health during salinity stress.
… temporally variable salinity. This review integrates physiological and biochemical responses to salinity with insights from multi-omics approaches, including transcriptomics, proteomics, …
… Introducing salt-tolerance genes from … Betaine aldehyde dehydrogenases (BADHs), which are key enzymes in glycine betaine (GB) biosynthesis, have been shown to enhance salt …
围绕“BADH/甜菜碱代谢—紫花苜蓿—盐胁迫/复合逆境”的研究,文献可概括为:①BADH及其在甜菜碱(GB)合成与逆境适应中的机制与进化;②BADH基因/甜菜碱代谢的遗传改造或功能证据(含对盐胁迫耐受的转基因验证与相关综述);③紫花苜蓿在盐胁迫或盐碱复合逆境下的组学与代谢表型解析(转录组/蛋白组/代谢组/整合组学);④紫花苜蓿在盐胁迫下的遗传基础与分子育种线索(GWAS/QTL/候选基因、WGCNA枢纽基因等);⑤更广义的盐胁迫生理-代谢响应与综合管理策略(含综述、跨物种/路径证据,用于机制框架补充)。