Narayan J Ashwin, Dharshini S, Manoj V M, Padmanabhan T S Sarath, Kadirvelu K, Suresha G S, Subramonian N, Ram Bakshi, Premachandran M N, Appunu C
1Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, 641007 India.
2DRDO-BU Center for Life Sciences, Bharathiar University Campus, Coimbatore, 641046 India.
3 Biotech. 2019 May;9(5):186. doi: 10.1007/s13205-019-1719-3. Epub 2019 Apr 24.
In this study, full-length (1282-1330 bp) α-expansin 1 () gene from three different accessions belonging to complex (-, - and spp. hybrid-) was isolated using RAGE technique and characterized. The intronic and coding regions of isolated expansin genes ranged between 526-568 and 756-762 bp, respectively. An open reading frame encoding a polypeptide of 252 amino acids was obtained from and commercial sugarcane hybrid, whereas 254 amino acids were obtained in , a wild relative of . Bioinformatics analysis of deduced protein revealed the presence of specific signature sequences and conserved amino acid residues crucial for the functioning of the protein. The predicted physicochemical characterization showed that the protein is stable in nature with instability index (II) value less than 40 and also clearly shown the dominance of random coil in the protein structure. Phylogenetic analysis revealed high conservation of among complex and related crop species, and . The docking study of protein showed the interaction with xylose, which is present in xyloglucan of plant cell wall, elucidated the role of the expansin proteins in plant cell wall modification. This was further supported by the subcellular localization experiment in which it is clearly seen that the expansin protein localizes in the cell wall. Relative expression analysis of gene in complex during drought stress showed high expression of the in comparison with and indicating possible role of in increased water-deficit stress tolerance in . These results suggest the potential use of for increasing the water-deficient stress tolerance levels in crop plants.
在本研究中，利用RAGE技术从属于复合体（-、-和 spp. 杂交种）的三个不同种质中分离出全长（1282 - 1330 bp）的α-扩张蛋白1（）基因并进行了表征。分离出的扩张蛋白基因的内含子和编码区分别在526 - 568 bp和756 - 762 bp之间。从和商业甘蔗杂交种中获得了一个编码252个氨基酸多肽的开放阅读框，而在的野生近缘种中获得了254个氨基酸。对推导蛋白的生物信息学分析揭示了特定特征序列和对蛋白功能至关重要的保守氨基酸残基的存在。预测的理化特性表明该蛋白在性质上是稳定的，不稳定指数（II）值小于40，并且还清楚地显示了蛋白结构中无规卷曲的主导地位。系统发育分析表明，在复合体以及相关作物物种、和中，具有高度保守性。对蛋白的对接研究表明其与木糖相互作用，木糖存在于植物细胞壁的木葡聚糖中，阐明了扩张蛋白在植物细胞壁修饰中的作用。亚细胞定位实验进一步支持了这一点，在该实验中可以清楚地看到扩张蛋白定位于细胞壁。在干旱胁迫下对复合体中基因的相对表达分析表明，与和相比，的表达较高，表明在提高对水分亏缺胁迫的耐受性方面可能发挥作用。这些结果表明，有可能用于提高作物对缺水胁迫的耐受性水平。
