Aerenchyma formation in the rice stem and its promotion by H2O2
Aerenchyma formation in the rice stem and its promotion by H2O2
复制标题
DOI：
10.1111/j.1469-8137.2010.03496.x
复制
发表时间：
2011-01-01
期刊：
影响因子：
9.4
通讯作者：
Sauter, Margret
中科院分区：
文献类型：
--
作者：
Steffens, Bianka;Geske, Thomas;Sauter, Margret
气体空间（通气组织）的形成是为了适应淹没，以促进气体交换.在水稻中，通气组织的形成是通过细胞死亡和裂解来完成的，但在细胞水平上对这一过程的认识还很有限。它被分析在响应淹没，乙烯和过氧化氢（H2 O2）处理，并在MT 2b：：Tos 17突变体。用四氮唑蓝和肾上腺素测定法检测O-2中心点。用3，3 '-二氨基联苯胺检测到H_2O_2。深水水稻品种品高56的所有节间都有通气组织组成性发育，但节上没有通气组织。在两个低地水稻品种中也观察到组成型通气组织的形成，尽管程度较低。大量的通气组织存在于较老的节间，并在每个节间的顶部，揭示发育梯度。浸没或乙烯释放化合物乙烯利处理促进通气组织形成在所有基因型分析。前充质细胞含有较少的淀粉，没有叶绿体，细胞壁较薄，并产生高水平的O-2中心点-和H2 O2与其他实质细胞相比。乙烯利促进O-2中心点的形成，H_2O_2促进通气组织的形成，并呈剂量依赖性。此外，H_2O_2清除剂MT 2b的基因下调促进通气组织的形成，通气组织的形成由活性氧介导。
P>Gas spaces (aerenchyma) form as an adaptation to submergence to facilitate gas exchange. In rice (Oryza sativa), aerenchyma develop by cell death and lysis, which are poorly understood at the cellular level.Aerenchyma formation was studied in rice stems by light microscopy. It was analyzed in response to submergence, ethylene and hydrogen peroxide (H2O2) treatment, and in the MT2b::Tos17 mutant. O-2 center dot- was detected with nitroblue tetrazolium and an epinephrine assay. H2O2 was detected with 3,3'-diaminobenzidine.Aerenchyma develop constitutively in all internodes of the deep-water rice variety Pin Gaew 56, but are absent from the nodes. Constitutive aerenchyma formation was also observed in two lowland rice varieties, albeit to a lesser degree. A larger number of aerenchyma are present in older internodes, and at the top of each internode, revealing developmental gradients. Submergence or treatment with the ethylene-releasing compound ethephon promoted aerenchyma formation in all genotypes analyzed. Pre-aerenchymal cells contain less starch, no chloroplasts, thinner cell walls and produce elevated levels of O-2 center dot- and H2O2 compared with other parenchymal cells. Ethephon promotes O-2 center dot- formation and H2O2 promotes aerenchyma formation in a dose-dependent manner. Further-more, genetic downregulation of the H2O2 scavenger MT2b enhances aerenchyma formation.Aerenchyma formation is mediated by reactive oxygen species.