Babbar Richa, Tiwari Lalit Dev, Mishra Ratnesh Chandra, Shimphrui Rinchuila, Singh Aditya Abha, Goyal Isha, Rana Surbhi, Kumar Ritesh, Sharma Vijyesh, Tripathi Gayatri, Khungar Lisha, Sharma Jaydeep, Agrawal Chhavi, Singh Garima, Biswas Tanya, Biswal Anup Kumar, Sahi Chandan, Sarkar Neelam K, Grover Anil
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India.
Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India; Department of Botany, University of Lucknow, Lucknow-226007, India.
Plant Sci. 2023 May;330:111639. doi: 10.1016/j.plantsci.2023.111639. Epub 2023 Feb 15.
Hsp101 chaperone is vital for survival of plants under heat stress. We generated transgenic Arabidopsis thaliana (Arabidopsis) lines with extra copies of Hsp101 gene using diverse approaches. Arabidopsis plants transformed with rice Hsp101 cDNA driven by Arabidopsis Hsp101 promoter (IN lines) showed high heat tolerance while the plants transformed with rice Hsp101 cDNA driven by CaMV35S promoter (C lines) were like wild type plants in heat stress response. Transformation of Col-0 plants with 4633 bp Hsp101 genomic fragment (GF lines) from A. thaliana containing both its coding and the regulatory sequence resulted in mostly over-expressor (OX) lines and a few under-expressor (UX) lines of Hsp101. OX lines showed enhanced heat tolerance while the UX lines were overly heat sensitive. In UX lines, silencing of not only Hsp101 endo-gene was noted but also transcript of choline kinase (CK2) was silenced. Previous work established that in Arabidopsis, CK2 and Hsp101 are convergent gene pairs sharing a bidirectional promoter. The elevated AtHsp101 protein amount in most GF and IN lines was accompanied by lowered CK2 transcript levels under HS. We observed increased methylation of the promoter and gene sequence region in UX lines; however, methylation was lacking in OX lines.
热休克蛋白101（Hsp101）伴侣蛋白对于植物在热胁迫下的存活至关重要。我们采用多种方法培育了带有额外拷贝Hsp101基因的转基因拟南芥株系。用拟南芥Hsp101启动子驱动的水稻Hsp101 cDNA转化的拟南芥植株（IN株系）表现出高耐热性，而用花椰菜花叶病毒35S启动子（CaMV35S）驱动的水稻Hsp101 cDNA转化的植株（C株系）在热胁迫反应方面与野生型植株相似。用来自拟南芥的包含编码序列和调控序列的4633 bp Hsp101基因组片段转化Col-0植株（GF株系），结果大多产生Hsp101的过表达（OX）株系和少数低表达（UX）株系。OX株系表现出增强的耐热性，而UX株系对热过度敏感。在UX株系中，不仅Hsp101内源基因沉默，胆碱激酶（CK2）的转录本也被沉默。先前的研究表明，在拟南芥中，CK2和Hsp101是共享双向启动子的共转录基因对。在热胁迫下，大多数GF和IN株系中AtHsp101蛋白量的增加伴随着CK2转录水平的降低。我们观察到UX株系启动子和基因序列区域的甲基化增加；然而，OX株系中不存在甲基化。
