Bhatia Shikha, Gangappa Sreeramaiah N, Kushwaha Ritu, Kundu Snehangshu, Chattopadhyay Sudip
National Institute for Plant Genome Research, New Delhi 110067, India.
Plant Physiol. 2008 May;147(1):169-78. doi: 10.1104/pp.108.118174. Epub 2008 Mar 28.
Light is an important factor for plant growth and development. We have identified and functionally characterized a regulatory gene SHORT HYPOCOTYL IN WHITE LIGHT1 (SHW1) involved in Arabidopsis (Arabidopsis thaliana) seedling development. SHW1 encodes a unique serine-arginine-aspartate-rich protein, which is constitutively localized in the nucleus of hypocotyl cells. Transgenic analyses have revealed that the expression of SHW1 is developmentally regulated and is closely associated with the photosynthetically active tissues. Genetic and molecular analyses suggest that SHW1 acts as a negative regulator of light-mediated inhibition of hypocotyl elongation, however, plays a positive regulatory role in light-regulated gene expression. The shw1 mutants also display shorter hypocotyl in dark, and analyses of shw1 cop1 double mutants reveal that SHW1 acts nonredundantly with COP1 to control hypocotyl elongation in the darkness. Taken together, this study provides evidences that SHW1 is a regulatory protein that is functionally interrelated to COP1 and plays dual but opposite regulatory roles in photomorphogenesis.
光是植物生长发育的重要因素。我们已经鉴定并对一个参与拟南芥幼苗发育的调控基因——白光下短胚轴1（SHW1）进行了功能表征。SHW1编码一种独特的富含丝氨酸-精氨酸-天冬氨酸的蛋白质，该蛋白质组成性地定位于下胚轴细胞的细胞核中。转基因分析表明，SHW1的表达受发育调控，且与光合活性组织密切相关。遗传和分子分析表明，SHW1作为光介导的下胚轴伸长抑制的负调控因子，然而，在光调控基因表达中发挥正调控作用。shw1突变体在黑暗中也表现出较短的下胚轴，对shw1 cop1双突变体的分析表明，SHW1与COP1在黑暗中控制下胚轴伸长时发挥非冗余作用。综上所述，本研究提供了证据表明SHW1是一种与COP1功能相关的调控蛋白，在光形态建成中发挥双重但相反的调控作用。
