WRKY Gene Silencing Enhances Tolerance to Salt Stress in Transgenic Tomato

Abstract

WRKY proteins are superfamily of transcription factors, which are up or down-regulated in response to biotic and abiotic stress though limited study has conducted on transcriptional repression of tomato WRKY genes to salt stress. Thus, this study was conducted on three transgenic tomato (Solanum lycopersicum L. cv. Moneymaker) T1 generation plants carrying RNAi constructs for WRKY5, WRKY12, and WRKY13 to identify WRKYs that can act as negative regulators and uncover associated gene expression. In vitro propagated transgenic and wild type (MM) seedlings were transferred to pots under greenhouse. The plants were watered with standard solution supplemented with 0 or 100 mM NaCl for 4 weeks and evaluated for their responses. The result showed WRKY12 and WRKY13_RNAi lines performed better under salt stress with successful silencing which suggest the two WRKY transcription factors act as negative regulators. SOS1 is up regulated in WRKY13_RNAi, which may lead to low Na⁺ accumulation and contribute to salt tolerance. Expression of APX is up regulated in WRKY12 and WRKY13_RNAi, which may contribute to salt tolerance mechanism of the two genotypes. Microarray analysis of abiotic stress related genes might give clear indication for the regulatory role of WRKY12 and WRKY13 in abiotic stress tolerance.

Keywords׃ Solanum lycopersicum. Salt Stress. WRKY_RNAi. Negative Regulator

DOI: 10.7176/JBAH/10-17-03

Publication date:September 30^th 2020