作为一种广泛存在于植物中的细胞壁松弛蛋白,已显示出expansin积极参与植物生长的调节和对环境胁迫的响应。野生大豆长期存在于野生环境中,具有丰富的抗病基因资源,对栽培大豆种质的改良具有重要价值。在我们之前的研究中,我们发现,野生大豆expansin基因GsEXLB14在根中特异性转录,在盐和干旱胁迫下,其转录水平显着增加。为了进一步鉴定GsEXLB14的功能,在本研究中,我们克隆了这个基因的CDS序列。通过qRT-PCR分析了盐和干旱胁迫下野生大豆根中GsEXLB14的转录模式。使用发根农杆菌介导的遗传转化,我们获得了过表达GsEXLB14的大豆毛状根。在150mMNaCl和100mM甘露醇模拟的干旱胁迫下,数字的相对增长值,长度,转基因大豆毛状根的重量明显高于对照组。我们通过RNA测序获得了正常生长条件下以及盐和干旱胁迫下转基因和野生型大豆毛状根的转录组。转录组学分析表明,编码expansin(EXPB家族)的基因的转录,过氧化物酶,H+转运ATP酶,在盐胁迫下,转基因发根中的其他基因显着上调。在干旱胁迫下,在转基因毛状根中,expansin(EXPB/LB家族)基因的转录增加。此外,编码过氧化物酶的基因的转录,钙/钙调蛋白依赖性蛋白激酶,和脱水反应蛋白显著增加。qRT-PCR的结果也证实了上述基因的转录模式与转录组一致。上述基因转录水平的差异可能是过表达GsEXLB14基因的大豆毛状根在盐和干旱胁迫下耐受性强的潜在原因。总之,expansinGsEXLB14可作为大豆分子育种的一个有价值的候选基因。
As a type of cell-wall-relaxing protein that is widely present in plants, expansins have been shown to actively participate in the regulation of plant growth and responses to environmental stress. Wild soybeans have long existed in the wild environment and possess abundant resistance gene resources, which hold significant value for the improvement of cultivated soybean germplasm. In our previous study, we found that the wild soybean
expansin gene GsEXLB14 is specifically transcribed in roots, and its transcription level significantly increases under salt and drought stress. To further identify the function of GsEXLB14, in this study, we cloned the CDS sequence of this gene. The transcription pattern of GsEXLB14 in the roots of wild soybean under salt and drought stress was analyzed by qRT-PCR. Using an Agrobacterium rhizogenes-mediated genetic transformation, we obtained soybean hairy roots overexpressing GsEXLB14. Under 150 mM NaCl- and 100 mM mannitol-simulated drought stress, the relative growth values of the number, length, and weight of transgenic soybean hairy roots were significantly higher than those of the control group. We obtained the transcriptomes of transgenic and wild-type soybean hairy roots under normal growth conditions and under salt and drought stress through RNA sequencing. A transcriptomic analysis showed that the transcription of genes encoding expansins (EXPB family), peroxidase, H+-transporting ATPase, and other genes was significantly upregulated in transgenic hairy roots under salt stress. Under drought stress, the transcription of
expansin (EXPB/LB family) genes increased in transgenic hairy roots. In addition, the transcription of genes encoding peroxidases, calcium/calmodulin-dependent protein kinases, and dehydration-responsive proteins increased significantly. The results of qRT-PCR also confirmed that the transcription pattern of the above genes was consistent with the transcriptome. The differences in the transcript levels of the above genes may be the potential reason for the strong tolerance of soybean hairy roots overexpressing the GsEXLB14 gene under salt and drought stress. In conclusion, the
expansin GsEXLB14 can be used as a valuable candidate gene for the molecular breeding of soybeans.