Just Accepted
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Short-term and long-term fluoride stress induce differential molecular and transcriptional regulation and variable ranges of fluoride tolerance in two indica rice varieties, Khitish and MTU1010
Ankur Singh, Aditya Banerjee,
Aryadeep Roychoudhury 
Abstract
The aim of this manuscript was to decipher the reprogramming of protective machineries and sulfur metabolism, as response to time-dependent effect of fluoride stress for 10 and 20 days in two rice cultivars. Unregulated accumulation of fluoride via chloride channel (CLC1 and CLC2) in 10 day-old and 20 day-old Khitish and MTU1010 seedlings, respectively, caused higher accumulation of H2O2 and superoxide anion which eventually incited chlorophyll loss and electrolyte leakage, along with the formation of malondialdehyde (MDA) and methylglyoxal (MG). Additionally, higher fluoride accumulation also enhanced lipoxygenase (LOX) and NOX activity which further aggravated the oxidative damages. However, in case of stressed 20 day-old Khitish and 10 day-old MTU1010 seedlings, plant growth was maintained with lesser oxidative damages due to up regulated expression of H+-ATPase and FEX along with the elevated level of cysteine and H2S which could be linked with higher activity of ATP-S, OASTL and DES. The activity of the enzymatic antioxidants (SOD, CAT, APX, GPoX and GPX) and level of non-enzymatic antioxidants (anthocyanins and flavonoids) were also enhanced that strengthened the antioxidative potential of the seedlings. Our work clearly demonstrated that differential reprogramming of the protective metabolites and sulfur assimilation pathways were largely responsible for the differential pattern of adaptive strategies against fluoride stress in the two varieties, viz., Khitish and MTU1010, the former exhibiting resilience against long-term stress, whilst the latter showing high susceptibility for the same.
FP23323 Accepted 03 December 2024
© CSIRO 2024
