Padaria Jasdeep Chatrath, Yadav Radha, Tarafdar Avijit, Lone Showkat Ahmad, Kumar Kanika, Sivalingam Palaiyur Nanjappan
National Research Centre on Plant Biotechnology, PUSA Campus, New Delhi, India.
International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Telangana, India.
Mol Biol Rep. 2016 Aug;43(8):849-59. doi: 10.1007/s11033-016-4013-z. Epub 2016 May 21.
Drought is a calamitous abiotic stress hampering agricultural productivity all over the world and its severity is likely to increase further. Abscisic acid-stress-ripening proteins (ASR), are a group of small hydrophilic proteins which are induced by abscisic acid, stress and ripening in many plants. In the present study, ZnAsr 1 gene was fully characterized for the first time from Ziziphus nummularia, which is one of the most low water forbearing plant. Full length ZnAsr 1 gene was characterised and in silico analysis of ZnASR1 protein was done for predicting its phylogeny and physiochemical properties. To validate transcriptional pattern of ZnAsr 1 in response to drought stress, expression profiling in polyethylene glycol (PEG) induced Z. nummularia seedlings was studied by RT-qPCR analysis and heterologous expression of the recombinant ZnAsr1 in Escherichia coli. The nucleotide sequence analysis revealed that the complete open reading frame of ZnAsr 1 is 819 bp long encoding a protein of 273 amino acid residues, consisting of a histidine rich N terminus with an abscisic acid/water deficit stress domain and a nuclear targeting signal at the C terminus. In expression studies, ZnAsr 1 gene was found to be highly upregulated under drought stress and recombinant clones of E. coli cells expressing ZnASR1 protein showed better survival in PEG containing media. ZnAsr1 was proven to enhance drought stress tolerance in the recombinant E.coli cells expressing ZnASR1. The cloned ZnAsr1 after proper validation in a plant system, can be used to develop drought tolerant transgenic crops.
干旱是一种灾难性的非生物胁迫，阻碍着全球农业生产力，而且其严重程度可能还会进一步加剧。脱落酸胁迫成熟蛋白（ASR）是一类小的亲水性蛋白，在许多植物中受脱落酸、胁迫和成熟诱导。在本研究中，首次从枣（一种极耐干旱的植物）中对ZnAsr 1基因进行了全面表征。对全长ZnAsr 1基因进行了表征，并对ZnASR1蛋白进行了电子分析，以预测其系统发育和理化性质。为了验证ZnAsr 1响应干旱胁迫的转录模式，通过RT-qPCR分析研究了聚乙二醇（PEG）诱导的枣幼苗中的表达谱，并在大肠杆菌中对重组ZnAsr1进行了异源表达。核苷酸序列分析表明，ZnAsr 1的完整开放阅读框长819 bp，编码一个由273个氨基酸残基组成的蛋白质，该蛋白质由一个富含组氨酸的N端、一个脱落酸/水分亏缺胁迫结构域和一个位于C端的核定位信号组成。在表达研究中，发现ZnAsr 1基因在干旱胁迫下高度上调，表达ZnASR1蛋白的大肠杆菌细胞重组克隆在含PEG的培养基中表现出更好的存活率。已证明ZnAsr1可增强表达ZnASR1的重组大肠杆菌细胞的耐旱性。在植物系统中经过适当验证后，克隆的ZnAsr1可用于培育耐旱转基因作物。
