Genetic Improvement of Tomato (Solanum lycopersicum) with AtDREB1A Gene for Cold Stress Tolerance using Optimized Agrobacterium-mediated Transformation System

Abstract

Cold is a serious threat that limits the productivity of tomato as it is a cold-sensitive crop. The cold tolerant gene DREB1A plays crucial roles in the survival of plants under cold stress. We have developed cold stress tolerant transgenic plants of tomato by the overexpression of an Arabidopsis DREB1A gene. They were obtained by using EHA-105 strain of Agrobacterium harboring pBIH binary vector that contained DREB1A controlled by an inducible promoter Lip9 and hygromycin phosphotransferase gene (hpt) as a plant selectable marker. Sequential 15 day old in vitro seedlings, 48 h preculture period, Agrobacterium density (OD600 nm = 0.2), 3 min infection period and 60 µM acetosyringone yielded 15-18% TE. T0 transformants were identified by PCR and then they were self-pollinated to generate T1 progeny that was evaluated by gene expression and cold tolerance analyses. AtDREB1A transcript expression was detected by RT-PCR and stable integration of AtDREB1A gene was confirmed by Southern blotting. Morphological analyses of T2 generations demonstrated that there were no significant differences among transgenic and NT plants under normal growth conditions. The T2 transgenic lines exhibited more cold stress tolerance when exposed to 4ºC as compared to their NT counterparts. These findings clearly indicate that transgenic tomato plants over-expressing Arabidopsis DREB1A gene enhanced protection and provided cold tolerance under controlled conditions in transgenic containment.

Impact of Climate Change on Crops Adaptation and Strategies to Tackle Its Outcome: A Review

“…There are numerous transgenic plants which have been established by genetic engineering to tackle the biotic and abiotic stresses. These genetically engineered plants demonstrate significant resistance against climatic variations compared to normal plants [ 165 , 166 ].…”

Comparative Physiology and Transcriptome Analysis of Young Spikes in Response to Late Spring Coldness in Wheat (Triticum aestivum L.)

“…In Arabidopsis thaliana, DREB1A regulates downstream gene expression by binding to the core sequence of A/GCCGAC in response to drought, high salt, and cold stress (Jia et al, 2016). The transgenic plants enhanced their cold tolerance by overexpressing AtDREB1A in tomatoes (Shah et al, 2016) and bottle gourd (Cho et al, 2017). Similarly, transgenic potato with AtDREB1B will also enhance its cold resistance (Movahedi et al, 2012).…”

Highly efficient Agrobacterium-mediated transformation and plant regeneration system for genome engineering in tomato

“…Diverse hygromycin concentrations have been successfully applied as a selection agent to recover transgenic plants in tomato ( Koul et al, 2014 , Prihatna et al, 2019 , Gadir et al, 2018 ). Pre-culturing of explants was successfully enhanced the transformation efficiency in different explants of several tomato genotypes ( Koul et al, 2014 , Shah et al, 2016 , Gadir et al, 2018 , Stavridou et al, 2019 ). Bacterial cell density was recorded as one of the most critical factors in improving tomato transformation efficiency ( Koul et al, 2014 , Gadir et al, 2018 ).…”