10.3389/fpls.2018.01869.s006 Uppala Lokesh Uppala Lokesh Boya Venkatesh Boya Venkatesh Kurnool Kiranmai Kurnool Kiranmai Ambekar Nareshkumar Ambekar Nareshkumar Vennapusa Amarnathareddy Vennapusa Amarnathareddy Gunupuru Lokanadha Rao Gunupuru Lokanadha Rao Anthony Masilamani Anthony Johnson Anthony Masilamani Anthony Johnson Merum Pandurangaiah Merum Pandurangaiah Chinta Sudhakar Chinta Sudhakar Image_6_Overexpression of ß-Ketoacyl Co-A Synthase1 Gene Improves Tolerance of Drought Susceptible Groundnut (Arachis hypogaea L.) Cultivar K-6 by Increased Leaf Epicuticular Wax Accumulation.tif Frontiers 2019 groundnut drought stress AhKCS1 epicuticular wax non-stomatal water loss transgenic plants 2019-01-11 04:32:01 Figure https://frontiersin.figshare.com/articles/figure/Image_6_Overexpression_of_-Ketoacyl_Co-A_Synthase1_Gene_Improves_Tolerance_of_Drought_Susceptible_Groundnut_Arachis_hypogaea_L_Cultivar_K-6_by_Increased_Leaf_Epicuticular_Wax_Accumulation_tif/7576385 <p>Drought is one of the major environmental constraints affecting the crop productivity worldwide. One of the agricultural challenges today is to develop plants with minimized water utilization and reduced water loss in adverse environmental conditions. Epicuticular waxes play a major role in minimizing water loss. Epicuticular wax covers aerial plant parts and also prevents non-stomatal water loss by forming the outermost barrier from the surfaces. Epicuticular wax content (EWC) variation was found to be affiliated with drought tolerance of groundnut cultivars. In the current study, a fatty acid elongase gene, KCS1, which catalyzes a rate limiting step in the epicuticular wax biosynthesis was isolated from drought tolerant cultivar K-9 and overexpressed in drought sensitive groundnut cultivar (K-6) under the control of CaMV35S constitutive promoter. Transgenic groundnut plants overexpressing AhKCS1 exhibited normal growth and displaying greenish dark shiny appearance. Environmental scanning electron microscopy (ESEM) revealed the excess of epicuticular wax crystal depositions on the transgenic plant leaves compared to non-transgenic wild type plants. The findings were further supported by gas chromotography–mass spectroscopic analysis (GC-MS) that revealed enhanced levels of fatty acids, secondary alcohols, primary alcohols, aldehydes, alkanes, and ketones in transgenics compared to wild types. The AhKCS1 overexpressing transgenic groundnut plants exhibited increase in the cuticular wax content, reduction of water loss, lower membrane damage, decreased MDA content, and high proline content compared to that of non-transgenic groundnut plants. Our findings suggest that the AhKCS1 gene plays a major role in combating drought stress by preventing non-stomatal water loss in drought sensitive groundnut cultivar (K-6).</p>