Elucidation of mechanisms governing selectable expression of chloroplast genes and its application to plant improvement

SIG1基因的修饰选择性地关闭了叶绿体的基因表达。我们通过蛋白质-蛋白质相互作用的体外检测，然后进行磷酸化实验，对拟南芥的cDNA克隆进行了全基因组筛选，从而鉴定了一些SIG-one蛋白激酶(SOPKs)。在优先激发PS I的光照条件下，SOPK基因敲除(KO)系PS I反应中心蛋白psaA基因的表达谱与SIG1处于非磷酸化状态一致。GFP与这些SOPKs的融合应用表明它们在胞浆中定位。Sigone蛋白磷酸酶(SOPH)候选基因也试图通过类似的策略进行鉴定。这种“光开关”被进一步用于叶绿体工程。而富含氨基酸的“九郎”绿茶，则是用在遮光条件下生长的茶叶制成的。对这些叶子进行了转录转录分析。

Gene expression in chloroplasts was selectively switched off by the modification of sigma factor 1 (SIG1). We performed genome-wide screening of Arabidopsis cDNA clones by in vitro detection of protein-protein interaction, followed by phosphorylation assay, resulting in identification of some SIG-one protein kinases (SOPKs). Under lighting conditions that preferentially excited PS I, expression profiles of the psaA gene for the reaction center protein of PS I in SOPK-knockout (KO) lines, were consistent with SIG1 being in its unphosphorylated state. Employment of GFP fused with these SOPKs revealed their localization in the cytosol. SIG-one protein phosphatase (SOPH) candidate genes were tried to be identified by similar strategies. This "light switch" was further employed for chloroplast engineering. On the other hand, "gyokuro" green tea enriched with amino acids, is made of tea leaves grown under a light-shaded condition. Such leaves were subjected to transcriptomic analysis.