NaCl胁迫下宁夏枸杞光合作用相关基因差异表达分析

Differential Expression of Photosynthesis-Related Genes in Lycium barbarum under NaCl Stress

宁夏枸杞是著名的耐盐药用植物,该研究通过室内水培试验,利用高通量测序技术和qRT-PCR技术检测了不同浓度NaCl胁迫(0、100、200、300 mmol/L)下宁夏枸杞叶片光合作用相关基因差异表达,并分析了其叶绿素含量、净光合速率、Rubisco活性的变化,以揭示宁夏枸杞在盐胁迫条件下光合机构及光合作用相关基因差异表达规律,为深入解析宁夏枸杞响应盐胁迫的光合机理奠定基础。结果表明:(1)用100、200、300 mmol/L NaCl胁迫处理7 d时宁夏枸杞分别有14、26、55个光合作用相关基因差异表达,且随着NaCl胁迫程度的增加下调表达基因多于上调表达基因。(2)qRT-PCR结果显示,宁夏枸杞的3个光合作用相关基因ATPε、CLH2、Lhcb3的相对表达量均随着NaCl胁迫程度的加深总体呈显著下降的趋势,qRT-PCR验证结果与RNA-seq测序结果基本一致。(3)随着NaCl胁迫程度的增加,宁夏枸杞叶片中的叶绿素a和叶绿素b含量以及净光合速率和Rubisco活性均呈显著下降的趋势,而类胡萝卜素含量变化不显著。研究认为,宁夏枸杞能通过诱导光合作用相关基因的差异表达来调控叶片光合活性以响应NaCl胁迫环境。

Lycium barbarum is a famous salt-tolerant medicinal plant, this study conducted through indoor hydroponics experiments. High-throughput sequencing technology and qRT-PCR technology were used to determine the differential expression of photosynthetic related genes in leaves of L. barbarum under different concentrations of NaCl(0, 100, 200, 300 mmol/L), and the changes of chlorophyll content, net photosynthetic rate and Rubisco activity were analyzed.The purpose of this study was to reveal the differential expression of photosynthetic mechanisms and photosynthesis related genes of L. barbarum under salt stress, which laid the foundation for further analysis of the photosynthetic mechanism of L. barbarum in response to salt stress.The results showed as follows:(1) 14, 26 and 55 photosynthesis related genes were differentially expressed when treated with 100, 200 and 300 mmol/L NaCl for 7 days, respectively, the down-regulated genes were more than up-regulated genes with the increase of NaCl stress.(2) The results of qRT-PCR showed that the relative expressions of ATPε, CLH2 and Lhcb3 of the three photosynthetic related genes of L. barbarum showed a significantly decreased trend with the increase of NaCl stress. The results of qRT-PCR verification were basically consistent with the results of RNA-seq sequencing.(3) With the increase of NaCl stress, the contents of chlorophyll a and chlorophyll b, the net photosynthetic rate and the activity of Rubisco in the leaves of L. barbarum decreased significantly, but the carotenoid content did not change significantly. It was suggested that L. barbarum could regulate leaf photosynthetic activity in response to NaCl stress by inducing the differential expression of photosynthesis related genes.