拟南芥花粉水合至萌发的超微结构观察  

Ultrastructure of Pollen Hydration to Germination in Arabidopsis

作　　者：孙田田 王彤 李善伟 SUN Tian-tian;WANG Tong;LI Shan-wei(College of Life Sciences/Shandong Agricultural University,Tai'an,271018,China)

机构地区：[1]山东农业大学生命科学学院,山东泰安271018

出　　处：《山东农业大学学报（自然科学版）》2024年第4期526-530,共5页Journal of Shandong Agricultural University：Natural Science Edition

基　　金：胞内类受体激酶FUNA调控花粉管珠柄导向的分子机理研究(31900262)。

摘　　要：被子植物花粉与柱头组织的相互作用决定花粉的水合和萌发,水合至萌发这一过程中花粉粒内的细胞器是如何变化的却知之甚少。为了探究花粉水合至萌发过程中不同细胞器的变化,利用透射电子显微镜对拟南芥花粉在水合至萌发的不同时间段进行了超微结构观察。结果表明,拟南芥花粉粒中富含大量的脂滴,且脂滴周围环绕一圈内质网。从花粉水合至花粉萌发期间,内质网和线粒体的构型发生显著变化。水合初期内质网高度扩张呈潴泡状,随后形态逐渐发育成熟,表现为细长的管状结构;线粒体则由最初嵴不发达的球状变成嵴为片状且基质减少的多形态线粒体。随着花粉萌发过程的进行,液泡数量增多、体积增大且呈极性分布。脂滴与液泡的分布呈正相关,随着萌发过程的进行,脂滴周围的内质网减少,大的脂滴不断进入液泡中。以上结果表明,在花粉水合至萌发阶段,内质网负责生成脂滴,脂滴进入液泡中进行降解。同时,内质网和线粒体的形态逐渐发育正常,这些都为花粉管的萌发提供物质和能量基础;此外,液泡与脂滴的极性分布可能与花粉粒在最佳的位点产生花粉管有关。In order to investigate the changes of various organelles during the process of pollen hydration to germination,we employed electron microscopy to examine the ultrastructure of Arabidopsis thaliana pollen grains at distinct time points throughout hydration and germination.Our results revealed that Arabidopsis pollen grains are rich in lipid droplets surrounded by an endoplasmic reticulum.During the transition from pollen hydration to pollen germination,both the endoplasmic reticulum and mitochondria underwent remarkable alterations in their configurations.In the early stages of hydration,the endoplasmic reticulum experienced substantial expansion,forming a vesicular structure before gradually reverting to its normal elongated tubular structure.The mitochondria evolved from an initial underdeveloped spherical shape to polymorphic mitochondrial with lamellar cristae and reduced matrix.As pollen germination progressed,the quantity and volume of vacuoles increased and showed polar distribution.The distribution of lipid droplets exhibited a positive correlation with vacuoles,with the process of germination,the endoplasmic reticulum around lipid droplets decreased,and large lipid droplets were continuously enter the vacuoles.These findings suggest that during the stages from pollen hydration to germination,the endoplasmic reticulum is responsible for the generation of lipid droplets,which subsequently enter vacuoles for degradation.Simultaneously,the development of the normal morphology of the endoplasmic reticulum and mitochondria supplies a material and energetic foundation for pollen tube germination.Moreover,the polar distribution of vacuoles and lipid droplets may be related to the optimal position of pollen tube.

关 键 词：拟南芥 花粉 细胞器 透射电镜 超微结构 

分 类 号：Q942.4[生物学—植物学] Q248