PDF(Pubmed)
Abstract：
BACKGROUND: Alfalfa (Medicago sativa L.) experiences many negative effects under salinity stress, which may be mediated by recurrent selection. Salt-tolerant alfalfa may display unique adaptations in association with rhizobium under salt stress.
RESULTS: To elucidate inoculation effects on salt-tolerant alfalfa under salt stress, this study leveraged a salt-tolerant alfalfa population selected through two cycles of recurrent selection under high salt stress. After experiencing 120-day salt stress, mRNA was extracted from 8 random genotypes either grown in 0 or 8 dS/m salt stress with or without inoculation by Ensifer meliloti. Results showed 320 and 176 differentially expressed genes (DEGs) modulated in response to salinity stress or inoculation x salinity stress, respectively. Notable results in plants under 8 dS/m stress included upregulation of a key gene involved in the Target of Rapamycin (TOR) signaling pathway with a concomitant decrease in expression of the SNrK pathway. Inoculation of salt-stressed plants stimulated increased transcription of a sulfate-uptake gene as well as upregulation of the Lysine-27-trimethyltransferase (EZH2), Histone 3 (H3), and argonaute (AGO, a component of miRISC silencing complexes) genes related to epigenetic and post-transcriptional gene control.
CONCLUSIONS: Salt-tolerant alfalfa may benefit from improved activity of TOR and decreased activity of SNrK1 in salt stress, while inoculation by rhizobiumstimulates production of sulfate uptake- and other unique genes.
RESULTS: To elucidate inoculation effects on salt-tolerant alfalfa under salt stress, this study leveraged a salt-tolerant alfalfa population selected through two cycles of recurrent selection under high salt stress. After experiencing 120-day salt stress, mRNA was extracted from 8 random genotypes either grown in 0 or 8 dS/m salt stress with or without inoculation by Ensifer meliloti. Results showed 320 and 176 differentially expressed genes (DEGs) modulated in response to salinity stress or inoculation x salinity stress, respectively. Notable results in plants under 8 dS/m stress included upregulation of a key gene involved in the Target of Rapamycin (TOR) signaling pathway with a concomitant decrease in expression of the SNrK pathway. Inoculation of salt-stressed plants stimulated increased transcription of a sulfate-uptake gene as well as upregulation of the Lysine-27-trimethyltransferase (EZH2), Histone 3 (H3), and argonaute (AGO, a component of miRISC silencing complexes) genes related to epigenetic and post-transcriptional gene control.
CONCLUSIONS: Salt-tolerant alfalfa may benefit from improved activity of TOR and decreased activity of SNrK1 in salt stress, while inoculation by rhizobiumstimulates production of sulfate uptake- and other unique genes.
摘要：
背景：紫花苜蓿（MedicagosativaL.）在盐度胁迫下经历许多负面影响，这可能是由反复选择介导的。耐盐苜蓿在盐胁迫下可能与根瘤菌表现出独特的适应性。
结果：为了阐明盐胁迫下对耐盐苜蓿的接种效果，这项研究利用了在高盐胁迫下通过两个轮回选择周期选择选择的耐盐苜蓿种群。在经历了120天的盐压力后，从8种随机基因型中提取mRNA，这些基因型在0或8dS/m盐胁迫下生长，有或没有接种Ensifermeliloti。结果显示320和176个差异表达基因（DEGs）在响应盐度胁迫或接种x盐度胁迫时受到调节，分别。在8dS/m胁迫下的植物中值得注意的结果包括上调涉及雷帕霉素靶(TOR)信号传导途径的关键基因,伴随SNrK途径的表达降低。盐胁迫植物的接种刺激了硫酸盐摄取基因的转录增加以及赖氨酸27-三甲基转移酶（EZH2）的上调，组蛋白3(H3),和阿戈诺特(以前，miRISC沉默复合物的组成部分）与表观遗传和转录后基因控制有关的基因。
结论：耐盐苜蓿可能受益于盐胁迫中TOR活性的提高和SNrK1活性的降低，而根瘤菌接种刺激硫酸盐摄取和其他独特基因的产生。
结果：为了阐明盐胁迫下对耐盐苜蓿的接种效果，这项研究利用了在高盐胁迫下通过两个轮回选择周期选择选择的耐盐苜蓿种群。在经历了120天的盐压力后，从8种随机基因型中提取mRNA，这些基因型在0或8dS/m盐胁迫下生长，有或没有接种Ensifermeliloti。结果显示320和176个差异表达基因（DEGs）在响应盐度胁迫或接种x盐度胁迫时受到调节，分别。在8dS/m胁迫下的植物中值得注意的结果包括上调涉及雷帕霉素靶(TOR)信号传导途径的关键基因,伴随SNrK途径的表达降低。盐胁迫植物的接种刺激了硫酸盐摄取基因的转录增加以及赖氨酸27-三甲基转移酶（EZH2）的上调，组蛋白3(H3),和阿戈诺特(以前，miRISC沉默复合物的组成部分）与表观遗传和转录后基因控制有关的基因。
结论：耐盐苜蓿可能受益于盐胁迫中TOR活性的提高和SNrK1活性的降低，而根瘤菌接种刺激硫酸盐摄取和其他独特基因的产生。
