绿豆子叶切段形成愈伤组织过程中蛋白质代谢的变化(简报)

CHANGES ON THE PROTEIN METABOLISM DURING THE CALLUS FORMATION FROM COTYLEDON SEGMENTS OF MUNG BEAN

前人有关植物外植体脱分化形成愈伤组织的生理生化变化的研究表明,植物切块脱分化形成愈伤组织过程中,呼吸作用。

Changes in protein contents,polyribo-some levels and proteolytic enzyme activi-ties were studied in cultured segments ofmung bean(Phaseolus radiatus L.cv.D317-1)cotyledons during callus formationunder an optimal phytohormone concentra-tion of 1 ppm KT and 4 ppm NAA in aMiller medium.Newly formed calli wereobserved on the segments after 5 days ofculture,and a large amount of calli for-med during the succeeding days.Duringthe 11 days of culture,the protein contentof the segments continuously decreased forthe first 5 days and then stabilized duringthe remaining 6 days.The activities ofproteinase in the newly cultured segmentswere relatively high,and even further in-creased when the segments started toform callus.The relative contents ofpolyribosomes,which represent the rateof protein synthesis,were substantiaellyenhanced and remained high during thecallus formation process.The amount offree amino acids which accumulated duringthe first 5 days of culture declined duringthe last 5—7 days.Thus,it may beconcluded that,in terms of proteinmetabolism,callus formation from culturedsegments of mung bean cotyledons ischaracterized not only by the persistentlyrapid degradation,but also by the activesynthesis of protein.