Backiyarani Suthanthiram, Anuradha Chelliah, Thangavelu Raman, Chandrasekar Arumugam, Renganathan Baratvaj, Subeshkumar Parasuraman, Giribabu Palaniappan, Muthusamy Muthusamy, Uma Subbaraya
ICAR-National Research Centre for Banana, Thogamalai Road, Thayanur Post, Tiruchchirappalli, Tamil Nadu 620 102 India.
Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), RDA, Jeonju, 54874 Korea.
3 Biotech. 2022 Apr;12(4):101. doi: 10.1007/s13205-021-03106-x. Epub 2022 Mar 28.
Expansin, a cell wall-modifying gene family, has been well characterized and its role in biotic and abiotic stress resistance has been proven in many monocots, but not yet studied in banana, a unique model crop. Banana is one of the staple food crops in developing countries and its production is highly influenced by various biotic and abiotic factors. Characterizing the expansin genes of the ancestor genome ( and ) of present day cultivated banana will enlighten their role in growth and development, and stress responses. In the present study, 58 (MaEXPs) and 55 (MbaEXPs) putative expansin genes were identified in A and B genome, respectively, and were grouped in four subfamilies based on phylogenetic analysis. Gene structure and its duplications revealed that EXPA genes are highly conserved and are under negative selection whereas the presence of more number of introns in other subfamilies revealed that they are diversifying. Expression profiling of expansin genes showed a distinct expression pattern for biotic and abiotic stress conditions. This study revealed that among the expansin subfamilies, EXPAs contributed significantly towards stress-resistant mechanism. The differential expression of and under drought stress conditions in the contrasting cultivar suggested their role in drought-tolerant mechanism. Most of the genes are differentially expressed in the root lesion nematode contrasting cultivars which speculated that this expansin subfamily might be the susceptible factor. The downregulation of in resistant cultivar during Sigatoka leaf spot infection suggested that by suppressing this gene, resistance may be enhanced in susceptible cultivar. Further, in-depth studies of these genes will lead to gain insight into their role in various stress conditions in banana.
The online version contains supplementary material available at 10.1007/s13205-021-03106-x.
扩张蛋白是一个细胞壁修饰基因家族，已得到充分表征，其在许多单子叶植物的生物和非生物胁迫抗性中的作用已得到证实，但在独特的模式作物香蕉中尚未进行研究。香蕉是发展中国家的主要粮食作物之一，其产量受到各种生物和非生物因素的高度影响。表征当今栽培香蕉祖先基因组（A和B）中的扩张蛋白基因将有助于了解它们在生长发育和胁迫反应中的作用。在本研究中，分别在A基因组和B基因组中鉴定出58个（MaEXPs）和55个（MbaEXPs）推定的扩张蛋白基因，并根据系统发育分析将它们分为四个亚家族。基因结构及其重复表明，EXPA基因高度保守且处于负选择之下，而其他亚家族中内含子数量较多表明它们正在多样化。扩张蛋白基因的表达谱显示了生物和非生物胁迫条件下独特的表达模式。这项研究表明，在扩张蛋白亚家族中，EXPAs对胁迫抗性机制有显著贡献。在对比品种中，干旱胁迫条件下MaEXPA1和MaEXPA8的差异表达表明它们在耐旱机制中的作用。大多数MaEXPB基因在根结线虫对比品种中差异表达，推测这个扩张蛋白亚家族可能是易感因素。在抗香蕉叶斑病品种感染香蕉叶斑病期间MaEXPA1的下调表明，通过抑制该基因，易感品种的抗性可能会增强。此外，对这些基因的深入研究将有助于深入了解它们在香蕉各种胁迫条件下的作用。
在线版本包含可在10.1007/s13205-021-03106-x获取的补充材料。
