PHYSIOLOGICAL AND MOLECULAR RESPONSES OF SUGARCANE GENOTYPES SUBJECTED TO HYPOXIA

Abstract

The present study focuses on changes in morphological, physiological and gene expression patterns in sugarcane, in response to waterlogging stress at seedling stage. Forty five days old seedlings were subjected to waterlogging for fifteen days. Significant reduction in seedling shoot length (16.5%) and root length (31.48%) were observed after 15 days of flooding. Irrespective of the genotypes, there was 2.5 fold increase in number of shoot roots under flooding treatments. Significant reduction in pigment content “chl a” (24.32%), “chl b” (30.67%) and total chlorophyll content (26.33%) were noticed due to flooding treatment in all the genotypes. Study of gene expression under flooding conditions by RT-PCR, revealed differential expression in tolerant and susceptible sugarcane genotypes. Up regulation of gene expression in flooded roots and shoots was observed for most of the candidate genes though root tissues showed more accumulation of transcripts when compared to the shoots. Highest transcript accumulation was observed for aldehyde dehydrogenase (ALDH), alcohol dehydrogenase (ADH), ACC (1-aminocyclopropane -1-carboxylate) oxidase and GBF1.