下胚轴
黄化
光敏色素
光敏色素A
苗木
拟南芥
拟南芥
突变体
生物
植物
野生型
细胞生物学
化学
遗传学
生物化学
基因
酶
红灯
作者
Marcelo J. Yanovsky,Jorge J. Casal,Garry C. Whitelam
标识
DOI:10.1111/j.1365-3040.1995.tb00582.x
摘要
ABSTRACT The roles of phytochrome A (phyA), phytochrome B (phyB) and a putative blue‐light (BL) photoreceptor (HY4) in the control of hypocotyl growth by natural radiation were investigated using phyA, phyB and hy4 mutants of Arabidopsis thaliana . Full sunlight inhibited hypocotyl growth to a larger extent in wild‐type (WT) than in phyA, phyB and, particularly, hy4 seedlings. In WT seedlings, hypocotyl growth was promoted by selectively lowering BL irradiance, lowering red‐light (R) plus far‐red‐light (FR) irradiance or lowering the R/FR ratio (which was achieved either by increasing FR or by reducing R). The effects of lowering BL were reduced in hy4 and exaggerated in phyA seedlings. The effects of lowering R+FR were reduced in phyA and exaggerated in hy4 seedlings. Neither phyB nor hy4 mutants responded to low R/FR ratios. Neighbouring plants reflecting FR without shading caused subtle reductions of the R/FR ratio. This signal promoted hypocotyl growth in WT but not in phyA, phyB or hy4 seedlings. Intermediate canopy shade produced similar effects in all genotypes. Under deep shade, de‐etiolation was severely impaired in phyA seedlings, which died prematurely. Thus, the FR ‘high‐irradiance reaction’ mediated by phyA could be important for seedling survival under dense canopies.
科研通智能强力驱动
Strongly Powered by AbleSci AI