Comparative Biochemical Analysis of High and Low Sucrose Accumulating Sugarcane Varieties at Formative Stage under Heat Stress

Abstract

Sugarcane (Saccharum officinarum L) is a valuable cash cropwhich plays an imperative role in the worldwide economy.However, high temperature has significantly retarded thecrop growth and yield by alteration of biochemical pathways.Therefore, the biochemical activities of two sugarcanevarieties were explored under heat stress condition. Thesugarcane cultivars S2003-US-633 (high sucroseaccumulation) and SPF-238 (low sucrose accumulation)were cultivated and subjected to different temperatureregimes i.e. control at 30±2 °C, heat stress at 45±2 °C andrecovery at 30±2 °C for 24, 48 and 72 hours at formativestage. Detailed profiling of physiochemical attributes, sugaranalysis linked with sucrose metabolism enzymes andthermotolerance indicators were investigated. S2003-US633 exhibited better response in terms of sugar accumulationregulated by sucrose synthase, sucrose phosphate synthaseand invertase activities along with more prolineaccumulation, total soluble protein contents with response tohigh temperature exposure. While S2003-US-633 is rankedas tolerant variety due to less MDA, H2O2 content andelectrolytes leakage exhibiting its efficient tolerancemechanism, giving high sugar recovery rate despite harshenvironmental conditions. Thus, these findings can behelpful in providing information for engineering sugarimprovement along with thermotolerance in sugarcanevarieties and providing new avenues towards the economicdevelopment of the country.