Polymeric hydrogel enhances PAHs resistance in wheat (Triticum aestivum L.) by lowering nitric oxide synthesis: an approach to alleviate abiotic stress
摘要
The role of polymeric hydrogel (PMH) in wheat's response to Benzo[a]pyrene (BaP) stress is acknowledged, although mechanisms involved are not fully understood and have never reported. The present research found that exposure to BaP stress fast increased endogenous jasmonic acid levels in wheat roots. Polymeric hydrogel alleviated BaP toxicity by reducing BaP absorption in shoot cell walls and roots, accomplished through up-regulation of BaP chelation and efflux-associated genes like OsCAL1, OsABCG36 and OsHMA3, while concurrently down-regulating transcript degrees of BaP uptake and translocation-associated genes, such as OsZIP5/7, OsNRAMP1/5, OsCCX2 and OsHMA2. A decrease in hemicellulose levels was noted in cell wall of roots. The mitigating effect of polymeric hydrogel on BaP accumulation depended on the inhibition of nitric oxide production, as the nitric oxide donor SNP may diminish this effect. In brief, polymeric hydrogel significantly lowered BaP levels in wheat by downregulating cell wall's ability to absorb BaP, likely by decreasing nitric oxide generation.
Graphical Abstract