Plastids Are Major Regulators of Light Signaling in Arabidopsis
Plastids Are Major Regulators of Light Signaling in Arabidopsis
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DOI：
10.1104/pp.112.193599
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发表时间：
2012-05-01
期刊：
影响因子：
7.4
通讯作者：
Larkin, Robert M.
中科院分区：
文献类型：
--
作者：
Ruckle, Michael E.;Burgoon, Lyle D.;Larkin, Robert M.
我们之前提供的证据表明质体信号调节光信号网络的下游组分，并且这种信号整合通过调节基因表达来协调叶绿体的生物发生和光环境和发育。我们通过分析拟南芥（Arabidopsis thaliana）的光和质体调节转录组来验证这些想法。我们发现，这些转录组中基因本体术语的丰富与光和质体信号的整合是一致的(1)下调光合作用并诱导功能失调叶绿体的修复和胁迫耐受；(2)帮助协调生长、昼夜节律和胁迫响应等过程与叶绿体功能的程度。然后，我们通过表征受光和质体信号调节的基因的T-DNA插入等位基因，测试了促进这种信号整合的因素是否也受光和质体信号调节，并编码被注释为有助于信号传导、转录或无已知功能的蛋白质。我们发现，这些突变等位基因中有很大一部分在脱去过程中诱导叶绿体的生物发生。我们量化了其中7个增强的去脱脱（终止）突变体中4个光合作用相关基因的表达，发现光合作用相关基因的表达减弱。这种衰减对于光系统II亚单位S的表达尤其显著。我们得出结论，光和质体信号的整合调节了许多有助于优化叶绿体功能的END基因，并且至少一些END基因影响光合作用相关基因的表达。
We previously provided evidence that plastid signaling regulates the downstream components of a light signaling network and that this signal integration coordinates chloroplast biogenesis with both the light environment and development by regulating gene expression. We tested these ideas by analyzing light-and plastid-regulated transcriptomes in Arabidopsis (Arabidopsis thaliana). We found that the enrichment of Gene Ontology terms in these transcriptomes is consistent with the integration of light and plastid signaling (1) down-regulating photosynthesis and inducing both repair and stress tolerance in dysfunctional chloroplasts and (2) helping coordinate processes such as growth, the circadian rhythm, and stress responses with the degree of chloroplast function. We then tested whether factors that contribute to this signal integration are also regulated by light and plastid signals by characterizing T-DNA insertion alleles of genes that are regulated by light and plastid signaling and that encode proteins that are annotated as contributing to signaling, transcription, or no known function. We found that a high proportion of these mutant alleles induce chloroplast biogenesis during deetiolation. We quantified the expression of four photosynthesis-related genes in seven of these enhanced deetiolation (end) mutants and found that photosynthesis-related gene expression is attenuated. This attenuation is particularly striking for Photosystem II subunit S expression. We conclude that the integration of light and plastid signaling regulates a number of END genes that help optimize chloroplast function and that at least some END genes affect photosynthesis-related gene expression.