摘要
硫氧还蛋白是一类广泛存在于植物中的低分子量氧化还原蛋白,在植物生长发育调控和逆境响应过程中发挥重要的调控功能。以小麦(TriticumaestivumL.)品种‘中国春’和‘洛旱2号’为材料,采用RT-RCR方法克隆了小麦硫氧还蛋白基因TaTrxh9,通过生物信息学方法分析了其染色体定位及序列特征,并利用qRT-PCR技术分析了该基因对渗透胁迫的响应模式。结果显示:(1)成功克隆到小麦TaTrxh9基因,序列分析发现TaTrxh9基因位于第1染色体群的短臂上,并将其3个部分同源基因命名为TaTrxh9-1AS、TaTrxh9-1BS和TaTrxh9-1DS。(2)TaTrxh9基因包含4个内含子,且在内含子区域3个部分同源基因间序列差异较大;3个部分同源基因的编码区序列一致性在98%以上,均编码131个氨基酸,且蛋白序列完全相同;TaTrxh9蛋白包含1个Trx-family保守域和CXXC氧化还原活性位点,三维结构预测分析显示该蛋白可形成典型的硫氧还蛋白空间结构,包括由4个α螺旋组成的外围框架和由5个反向平行的β折叠组成的中心轴。(3)qRT-PCR分析显示,TaTrxh9基因受干旱胁迫诱导在叶片中下调表达,而在根系中呈先上调后下调的表达模式;盐胁迫过程中,TaTrxh9基因在叶片中无显著响应,在根系中也仅出现短暂的诱导表达现象;在ABA处理过程中,TaTrxh9基因表达模式与其对干旱胁迫的响应模式类似。研究推测,TaTrxh9基因对干旱胁迫的响应过程可能与ABA介导的基因表达调控有关。
Thioredoxins are a kind of low molecular weight redox proteins widely existing in plants, which play important roles in the developmental regulation and stress responding processes in plants. Two wheat(Triticum aestivum L.) cultivars, ‘Chinese Spring’ and ‘Luohan No. 2’, were used in this study. A thioredoxin gene TaTrxh9 was cloned from common wheat by using RT-PCR. Bioinformatics analysis was performed to define the chromosomal localization and sequence characteristics of TaTrxh9, and its expression patterns responding to osmotic stresses were detected by qRT-PCR. The results showed that:(1) TaTrxh9 gene was successfully cloned, sequence analysis indicated that TaTrxh9 was located on the short arms of group one chromosomes, and three homoeologues of the gene were designated as TaTrxh9-1AS, TaTrxh9-1BS and TaTrxh9-1DS, respectively.(2) Four introns were detected in each of TaTrxh9 homoeologues and a large number of polymorphisms were detected in introns among homoeologues, while the coding regions of homoeologues were highly identical(>98%) and encoded an identical protein sequence with the length of 131 amino acids. Characterization of TaTrxh9 protein indicated that a TRX-family conserved domain and a CXXC redox active site was detected, and the TaTrxh9 was predicted to have a typical spatial structure of thioredoxin, including a peripheral framework composed of 4 helixes and a central axis composed of 5 antiparallel β sheets.(3) qRT-PCR analysis showed that TaTrxh9 gene was down-regulated in leaves under drought stress, while initially increased and then declined in roots. Under salt stress, no significant response of TaTrxh9 gene was detected in leaves and only a transient induction was observed in roots. The expression pattern of TaTrxh9 under treatment of ABA is similar to that under the drought stress. It was speculated that the responding process of TaTrxh9 gene to drought stress was associated with ABA-mediated regulation of gene expression.
作者
李梦园
樊亚栋
张新宁
姜玉梅
孟凡荣
李永春
LI Mengyuan;FAN Yadong;ZHANG Xinning;JIANG Yumei;ZHANG Li;MENG Fanrong(College of Life Science, Henan Agricultural University, Zhengzhou 450002, China;College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2019年第5期896-903,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31571655)
国家重点研发计划(2017YFD0301101)
河南省自然科学基金(182300410051)
河南省留学人员科研择优资助项目
