Department of Biological Sciences, Tôkohu University, Kawauchi, Sendai 980, Japan.
Plant Physiol. 1976 Apr;57(4):547-52. doi: 10.1104/pp.57.4.547.
The effect of red light on the aging progression of the bean (Phaseolus vulgaris L.) hypocotyl segment unit was examined in relation to dwarfism using Kentucky Wonder (tall) and Masterpiece (dwarf) varieties. In both plants, red light promoted the elongation of younger zones and inhibited that of mature zones. The zone exhibiting maximum elongation was shifted to the younger zones by red light irradiation regardless of the plant type, but its extent was greater in the dwarf than in the tall. Thus, red light hastens both the beginning of elongation in the younger portion and its termination in the mature portion of the hypocotyl, particularly of the dwarf plant. These red light responses in each zone of both the tall and dwarf hypocotyl units were reversed by subsequent exposure to far red light regardless of the duration and intensity of red light, thus indicating that the hastened aging progression of the hypocotyl by red light is mediated by phytochrome. However, there is no difference in the rate of decay of Pfr between the tall and dwarf hypocotyls.The increased expression of bean dwarfism seems to result from a concerted action of red light upon the maturation of younger portions of the hypocotyls, which is more rapid in the dwarf than in the tall, and upon the elongation of the relatively matured portion, which is more severely inhibited in the dwarf.
用肯塔基州奇观（高）和杰作（矮）品种研究了红光对菜豆下胚轴节段单位衰老进展的影响与矮化有关。在这两种植物中，红光促进了年轻区的伸长，抑制了成熟区的伸长。无论植物类型如何，红光照射都会将伸长最大的区域转移到年轻区，但在矮化植物中比在高大植物中更为明显。因此，红光加速了下胚轴年轻部分的伸长开始和成熟部分的终止，尤其是矮化植物。无论红光的持续时间和强度如何，高、矮下胚轴各区域的这些红光反应都被随后的远红光暴露所逆转，这表明红光加速下胚轴衰老的进展是由光敏色素介导的。然而，高大和矮小下胚轴中 Pfr 的衰减率没有差异。豆矮化的表达增加似乎是由于红光对下胚轴年轻部分的成熟的协同作用，在矮化植物中比在高大植物中更快，以及对相对成熟部分的伸长的协同作用，在矮化植物中受到更严重的抑制。
