IN VITRO DEVELOPMENT OF SALINITY STRESS TOLERANT TOMATO _Solanum lycopersicum L cv Pusa Ruby_ PLANTS AND ETHYLENE MEDIATED PHYSIOLOGICAL AND MOLECULAR RESPONSES

Abstract

Overpopulation and environmental confrontation2s are the major issu2 es to be addressed immediately in order to meet the food demand. Tomato is a regular vegetable and well known for its health benefits, antioxidants, vitamins and its anti-carcinogenic nature due the presence of lycopene. Salinity is one of the major challenges that hinder agricultural productivity. Tomato (Solanum lycopersicum L.) is a nominated model among the dicotyledon crops to study the salt tolerance. The present study is aimed to develop the salt tolerant tomato by elucidating novel routs of salinity stress tolerance pathways involving important stress hormone of ethylene and salt overly sensitive (SOS) pathways and their interactions with salicylic acid. Here, we have performed in vitro culture method, leaf disc assay, in silico RNA-seq expression data profiling through heat map, quantitative real time PCR (qRT-PCR), gas liquid chromatography (GLC) and enzymes assay (1-aminocyclopropane 1-carboxylic acid, ACS2; nitrate reductase and antioxidants), and determination of shoot and root length, leaf number, leaf area, shoot and root wight and fruit size, proline level, electrolyte leakage, relative water content and water potential, sodium (Na+) and potassium (K+) content, K+/Na+ ratio, and photosynthetic parameters such as intercellular CO2 , stomatal conductance, Rubisco and net photosynthesis in wild type and in vitro developed IV-97 tomato cv. Pusa Ruby plants under salinity stress. Forty-five days-old plants are evaluated with differential concentrations of sodium chloride, ethrel , ethylene inhibitors (ETI) and the phenolic compound salicylic acid . The WT type and IV-97 plants were treated with H2 O (control), 250 mM NaCl, 250 mM NaCl along with 5 mM ethrel , 250 mM NaCl along with 100 µM silver nitrate, 250 mM NaCl along with 100 µM cobalt chloride, and 250 mM NaCl plus 100 µM salicylic acid.