Thiourea mediates alleviation of UV-B stress-induced damage in the Indian mustard ( Brassica juncea L.)

[摘要] UV-Bradiation (280-320 nm) as an environmental stress has damaging effect on plants and its overexposure can potentially interfere with growth and development. The effect of thiourea (TU) on UV-Bstress tolerance of 10-day-old Brassica juncea seedlings subjected to supplementary UV-Bfor 5 days was investigated. An increase in the UV-Babsorbing compounds anthocyanin, flavonoids and phenolic compounds was observed in UV-BTU treated seedlings as compared to that of control. The enhanced synthesis of UV-Bscreening compounds resulted in lesser damage to chlorophyll and also gain in fresh weight and dry weight in UV-BTU as compared to UV-B alone treatment. The enzymatic activities of guaiacol peroxidase (GPX) and superoxide dismutase (SOD) also increased in UV-BTU. The expression profiling of phenylalanine ammonia lyase (pal) and chalcone synthase (chs) indicated an upregulation under UV-BTU treatment, compared to that of control, suggesting that TU treatment ensured an early and efficient induction of flavonoid biosynthetic pathway. The results indicate that TU helps in ameliorating the damaging effects of UV-Bstress by efficiently maintaining the antioxidant status and attenuating the penetration of the UV-B.

[学科分类] 纳米科学和纳米技术

[关键词] Brassica;UV-B stress;thiourea;anthocyanins;antioxidant enzymes;gene expression