棉纤维细胞伸长生长与过氧化物酶和IAA氧化酶的关系

棉纤维细胞于开花当天从棉胚珠表皮上发生,随即开始伸长生长,星S型生长曲线。棉纤维细胞的可溶性蛋白、过氧化物酶活性和IAA氧化酶活性同伸长生长的关系不大;而离子型结合的细胞壁蛋白质含量、过氧化物酶活性和IAA氧化酶活性同棉纤维细胞的伸长生长关系较大,表现在棉纤维细胞快速伸长期活性较低,而在伸长生长停止时出现活性高峰,同棉纤维细胞的伸长生长有负相关现象。

A STUDY OF ELONGATION OF THE COTTON FIBRE CELL

Morphological initiation and growth kinetics of the cotton (Gossypium hirsutum L.cv. Daizi-15) fibre cell have been studied with the scanning electron microscope and the microcomputer respectively. The protein contents, peroxidase and IAA oxidase activities of the soluble part, the ionically wall-bound part and the extracellular part were also investigated during the same period of elongation, It was shown that the fibre cells were initiated on the day of flowering. At first, the initial cells were extruded from the epidermal cells of the cotton ovule, and then became global cells on the next day of flowering. On the second day after flowering, the initial cells elongated into fibre cells. The elongation period was twenty-four days. The growth curve of elongation was typically sigmoid. The soluble protein content, and the activities of peroxidase and IAA oxidase had less distinct relationships with the cotton fibre cell elongation. However, the wall-bound and the extracelullar protein content, and the activities of the peroxidase and IAA oxidase of these two parts recorded low levels during the rapid elongation phase and high levels when the elongation of the cotton fibre cells were ceasing, a peak appearing on the 20th day after flowering. It was concluded that the wall-bound peroxidase and/or IAA oxidase were correlated with the cessation of cotton fibre cell elongation. The possible mechanisms of the actions of these two enzymes in the cotton fibre cells were discussed.