tailieunhanh - Báo cáo khoa học: CAP2 enhances germination of transgenic tobacco seeds at high temperature and promotes heat stress tolerance in yeast

We reported earlier that ectopic expression of CAP2, a single AP2 domain containing transcription activator from chickpea (Cicer arietinum)in tobacco improves growth and development, and tolerance to dehydration and salt stress, of the transgenic plants. | CAP2 enhances germination of transgenic tobacco seeds at high temperature and promotes heat stress tolerance in yeast Rakesh Kumar Shukla Vineeta Tripathi Deepti Jain Rajiv Kumar Yadav and Debasis Chattopadhyay National institute of Plant Genome Research Aruna Asaf Ali Marg New Delhi India Keywords CAP2 chickpea heat stress tobacco yeast Correspondence D. Chattopadhyay National institute of Plant Genome Research Aruna Asaf Ali Marg New Delhi 110067 India Fax 91 11 26741658 Tel 91 11 26735189 E-mail debasis_chattopadhyay@ Present address Central institute of Medicinaland Aromatic Plants Lucknow India Received 16 June 2009 revised 13 July 2009 accepted 16 July 2009 doi We reported earlier that ectopic expression of CAP2 a single AP2 domain containing transcription activator from chickpea Cicer arietinum in tobacco improves growth and development and tolerance to dehydration and salt stress of the transgenic plants. Here we report that in addition the CAP2-transgenic tobacco seeds also exhibit higher germination efficiency at high temperature and show higher expression levels of genes for tobacco heat shock proteins and a heat shock factor. CAP2 was able to activate the 5 -upstream activating sequence of tobacco heat shock factor. Surprisingly expression of CAP2 cDNA in Saccharomyces cerevisiae also enhanced heat tolerance with increased expression of the gene for yeast heat shock factor 1 Hsf1 and its target the gene for yeast heat shock protein 104 Hsp104 . Sequence analysis of the Hsfl promoter revealed the presence of a dehydration-responsive element C-repeat-like element DRE CRE . Recombinant CAP2 protein bound to the DRE CRE in the Hsf1 promoter in a gel shift assay and transactivated the Hsf1 promoter-His reporter construct. The full-length CAP2 protein was required to provide thermotolerance in yeast. If these findings are taken together our results suggest that CAP2 is involved in the heat stress response and .