UV-B辐射对不同品种(品系)辣椒幼苗光合特性及UVR8表达的影响

Effects of UV-B radiation on photosynthetic characteristics and UVR8 expression in different pepper seedlings

为了解紫外线B(UV-B)辐射对辣椒(Capsicum annuum L.)光合特性及UV-B应答基因UVR8表达量的影响,以青海省主栽的9个辣椒品种(品系)为试验材料,紫外线处理剂量为28.56 kJ/(m^(2)·d),设空白对照(无照射),测定幼苗叶片光合特性、形态指标等14个指标,同时利用实时荧光定量PCR技术检测UVR8基因在各试验材料中的相对表达量。结果表明,与对照相比,处理组辣椒的叶绿素、类胡萝卜素含量总体降低,光合指标总体下降,从而抑制叶片光合作用,总体上UV-B处理对华美105大多数光合指标的影响较大,对乐都长辣椒的影响较小。荧光定量PCR检测结果显示,UV-B处理后,UVR8在华美105中的相对表达量上升幅度最大且与对照间的差异达显著水平。综合分析可知,华美105的大多数指标显著受到抑制,光能利用率降低,因此华美105为UV-B敏感型品种,且UVR8在该品种中的表达水平较高,说明UVR8能够在不耐紫外辐射辣椒品种(品系)中积极响应UV-B胁迫。

In order to understand the effects of ultraviolet B(UV-B)radiation on photosynthetic characteristics and UV-B response gene UVR8 expression of capsicum(Capsicum annuum L.),nine varieties(lines)of capsicum in Qinghai province were selected as test materials,the treatment dose was 28.56 kJ/(m^(2)·d),and blank control was set.A total of 14 indices such as photosynthetic characteristics and morphological indices of seedling leaves were determined.Meanwhile,the expression level of UVR8 was detected by real-time fluorescence quantitative PCR.The results showed that compared with the control,the chlorophyll and carotenoid contents in the treatment group were generally reduced,and the photosynthetic characteristics generally decreased,which inhibited the photosynthesis of leaves.Overall,UV-B treatment had a greater effect on most photosynthetic indices of Huamei 105,and a smaller effect on Ledu long pepper.The results of fluorescence quantitative PCR showed that the relative expression of UVR8 in Huamei 105 increased the most after UV-B treatment and was significantly higher than that in the control group.In conclusion,most indices of Huamai 105 were significantly inhibited,and the utilization rate of light energy was decreased.Therefore,Huamei 105 was a UV-B sensitive variety,and UVR8 was expressed at a high level in this variety,indicating that UVR8 could actively respond to UV-B stress in the varieties that were not resistant to ultraviolet radiation.