Long J C, Jenkins G I
Plant Molecular Science Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, Bower Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
Plant Cell. 1998 Dec;10(12):2077-86. doi: 10.1105/tpc.10.12.2077.
UV and blue light are important regulators of plant gene expression and development. We investigated the signal transduction processes involved in the induction of chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) gene expression by UV-B and UV-A/blue light in an Arabidopsis cell suspension culture. Experiments with electron transport inhibitors indicated that plasma membrane redox activity is involved in both signal transduction pathways. Calcium ionophore treatment stimulated expression of the TOUCH3 gene, and this induction was strongly antagonized by UV-A/blue and UV-B light, suggesting that both light qualities may promote calcium efflux from the cytosol. Consistent with this hypothesis, experiments with specific inhibitors indicated that UV-B and UV-A/blue light regulate calcium levels in a cytosolic pool in part via the action of specific Ca2+-ATPases. On the basis of these and previous findings, we propose that plasma membrane redox activity, initiated by photoreception, is coupled to the regulation of calcium release from an intracellular store, generating a calcium signal that is required to induce CHS expression.
紫外线和蓝光是植物基因表达和发育的重要调节因子。我们研究了拟南芥细胞悬浮培养物中紫外线B以及紫外线A/蓝光诱导查尔酮合酶（CHS）和苯丙氨酸解氨酶（PAL）基因表达所涉及的信号转导过程。用电子传递抑制剂进行的实验表明，质膜氧化还原活性参与了这两条信号转导途径。钙离子载体处理刺激了TOUCH3基因的表达，而紫外线A/蓝光和紫外线B强烈拮抗这种诱导作用，这表明这两种光质可能促进钙离子从细胞质中流出。与这一假设一致，用特异性抑制剂进行的实验表明，紫外线B和紫外线A/蓝光部分通过特定Ca2 + -ATP酶的作用来调节细胞质库中的钙水平。基于这些以及之前的研究结果，我们提出，由光感受引发的质膜氧化还原活性与细胞内钙库中钙释放的调节相偶联，产生诱导CHS表达所需的钙信号。
