Butt Hamama Islam, Yang Zhaoen, Chen Eryong, Zhao Ge, Gong Qian, Yang Zuoren, Zhang Xueyan, Li Fuguang
State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
PLoS One. 2017 Jan 26;12(1):e0170578. doi: 10.1371/journal.pone.0170578. eCollection 2017.
Drought stress can trigger the production of ABA in plants, in response to adverse conditions, which induces the transcript of stress-related marker genes. The R2R3 MYB TFs are implicated in regulation of various plants developmental, metabolic and multiple environmental stress responses. Here, a R2R3-MYB cloned gene, GaMYB62L, was transformed in Arabidopsis and was functionally characterized. The GaMYB62L protein contains two SANT domains with a conserved R2R3 imperfect repeats. The GaMYB62L cDNA is 1,017 bp with a CDS of 879, encodes a 292-residue polypeptide with MW of 38.78 kD and a pI value of 8.91. Overexpressed GaMYB62L transgenic Arabidopsis have increased proline and chlorophyll content, superior seed germination rate under salt and osmotic stress, less water loss rate with reduced stomatal apertures, high drought avoidance as compared to WT on water deprivation and also significant plant survival rates at low temperature. In addition, overexpressed GaMYB62L lines were more sensitive to ABA mediated germination and root elongation assay. Moreover, ABA induced GaMYB62L overexpression, enhanced the expression of ABA stress related marker genes like RD22, COR15A, ADH1, and RD29A. Together, overexpression of GaMYB62L suggested having developed better drought, salt and cold tolerance in transgenic Arabidopsis and thus presented it as a prospective candidate gene to achieve better abiotic stress tolerance in cotton crop.
干旱胁迫可促使植物产生脱落酸（ABA），以应对不利条件，进而诱导胁迫相关标记基因的转录。R2R3 MYB转录因子参与调控植物的各种发育、代谢及多种环境胁迫反应。在此，一个克隆的R2R3-MYB基因GaMYB62L被转入拟南芥并对其进行功能鉴定。GaMYB62L蛋白含有两个SANT结构域，具有保守的R2R3不完全重复序列。GaMYB62L cDNA为1017 bp，编码序列（CDS）为879 bp，编码一个由292个氨基酸残基组成的多肽，分子量为38.78 kD，等电点为8.91。过表达GaMYB62L的转基因拟南芥脯氨酸和叶绿素含量增加，在盐胁迫和渗透胁迫下种子萌发率更高，水分流失率更低，气孔孔径减小，在缺水条件下比野生型具有更高的耐旱性，在低温下也具有显著的植株存活率。此外，过表达GaMYB62L的株系对ABA介导的种子萌发和根伸长试验更敏感。而且，ABA诱导GaMYB62L过表达，增强了ABA胁迫相关标记基因如RD22、COR15A、ADH1和RD29A的表达。总之，GaMYB62L的过表达表明转基因拟南芥具有更好的耐旱、耐盐和耐寒性，因此它是实现棉花作物更好的非生物胁迫耐受性的一个潜在候选基因。
