丛生竹发笋成竹过程中内源激素的分配与变化规律

以佯黄竹(学名待定)、梁山慈竹(Dendrocalamus farinosus)、硬头黄竹(Bambusa rigida)和慈竹(Neosinocalamus affinis)4个竹种为研究对象,采用酶联免疫法(ELISA法)研究了丛生竹发笋成竹期内不同组织(部位)的5种内源激素含量变化。结果表明:1)总体上,激素含量的高低顺序均为脱落酸(ABA)>吲哚乙酸(IAA)>细胞分裂素(CTK)>赤霉素(GA)>油菜素内酯(BR),但活性高低可能正好相反;2)从组织(部位)上的分配看,IAA、CTK、BR三种激素在笋体或幼竹上、中、下部含量基本相当(除佯黄竹外,1a生竹叶片中的CTK含量明显低于其他组织),而ABA中部≥下部>上部,GA中部>上部>下部;3)五种激素表现出较强的协同作用,且与组织生长分化的活跃度相关,其中,IAA、ABA和GA在笋-竹发育过程中大体呈现"高-低-高"的变化趋势,CTK和BR则呈"先高后低"或"先升后降"的变化规律;4)丛生竹内源激素随其发育阶段的变化可能是细胞分裂、节间生长和抽枝展叶的迫切程度决定的,其中,ABA可能与对水分的需求程度及立地水分条件有关,而GA控制笋-幼竹高生长的专一性较其他激素强。研究可为丛生竹林生长与产出的激素调控提供基础数据。

Distribution Pattern and Dynamics of Endogenous Hormones in Four Sympodial Bamboo Species during the Shooting and Young Bamboo Stage

The enzyme-linked immunosorbent assay(ELISA)method was used in the present study to detect five endogenous hormones in various tissues(or positions)of four sympodial bamboo species,including Yanghuang Bamboo(scientific name not to be determined),Dendrocalamus farinosus,Bambusa rigida,and Neosinocalamus affinis,during the shooting and young bamboo stage.The results showed that:1)Overall,the order of hormone content was abscisic acid(ABA)>indoleacetic acid(IAA)>cytokinin(CTK)>gibberellic acid(GA)>brassinolide(BR),but the bioactivity may be just the opposite;2)Based on the distribution of tissues(positions),the contents of IAA,or CTK,or BR in bamboo shoots or young bamboos were statistically the same in the upper,middle and bottom positions(except Yanghuang bamboo,the CTK content in the leaves of 1-yr-old bamboo was significantly lower than that in other tissues).For ABA content,the trend was middle≥bottom>upper,but for GA content,the trend was middle>upper>bottom.3)The five hormones displayed strong synergistic effect and they were related to the activities of growth and differentiation of specific tissues or positions.Generally,IAA,ABA and GA showed a"high-low-high"variation,,while CTK and BR showed a"first high and then low"or"first rise and then fall"variation during the shoot-young bamboo stage.4)The dynamics of these endogenous hormones in sympodial bamboos with the development stages might be determined by the urgent demand of cell division,internode elongation and branch(leaf)emergence.Among them,ABA might be related to the degree of water demand and the soil moisture,while GA was more specific than other hormones in controlling the height growth of bamboo shoots and young bamboos.The present study can provided fundamental data for hormone regulation of growth and yield of sympodial bamboo forests.