大白菜小植株突变体s1光合能力及光反应相关基因的转录组分析

Photosynthetic capacity and transcriptome analysis of genes related to light reaction of small plant mutant s1 in Chinese cabbage

植株的大小与光合能力密切相关。本研究以大白菜小植株突变体s1和其野生型WT为材料,通过测定叶绿素含量、净光合速率、叶绿素荧光参数以及对光反应相关基因的转录水平分析,解析大白菜植株大小与光合能力的相关性。结果表明:与野生型相比,大白菜小植株突变体s1的叶绿素含量无显著差异,但光合速率显著降低29%;Fv/Fm和Y(II)值在二者之间无显著差异(P>0.05),而s1的外叶和新叶ETR值都显著低于WT;进一步的转录组分析表明光合电子传递链上的PSII、PC、FNR、ATP合酶相关基因表达下调0.94~1.69倍。由此证实,大白菜小植株突变体s1光合速率低与光合电子传递链中的基因表达下降及光合电子传递速率下降有关。该研究为进一步挖掘大白菜植株大小相关的优异基因资源提供了良好的试验材料,也为大白菜分子设计育种提供了理论依据。

Plant size is closely related to photosynthetic capacity.In this study,small plant mutant s1 and its wildtype were used as materials.The correlation between plant size and photosynthetic capacity of Chinese cabbage was analyzed through the determination of chlorophyll content,net photosynthetic rate,fluorescence parameters and transcriptional level analysis of genes related to light reaction.The results showed that there was no significant difference in chlorophyll content between mutant s1 and its wild type(WT),but the photosynthetic rate of s1 was significantly lower than that of WT.There was no significant difference in Fv/Fm and Y(II)values between s1 and WT,while the ETR values of outer and new leaves of s1 were significantly lower than that of WT.RNA-seq analysis confirmed that genes related to PSII,PC,FNR and ATP synthase on photosynthetic electron transport chain were down-regulated by 0.94-1.69.It was confirmed that the low photosynthetic rate of small plant mutant s1 of Chinese cabbage was related to the decrease of gene expression and photosynthetic electron transport rate in photosynthetic electron transport chain.This research provides a good experimental material for further exploring the excellent gene resources related to plant size of Chinese cabbage,and also provides a theoretical basis for molecular design breeding of Chinese cabbage.