Neutral Lipids in the Flowers of Arabidopsis Mutants

植物有性繁殖是一个动态的过程，其机制和调控是复杂的。对开花和结果的分子基础的研究在农业上既有实用价值，也有智力上的吸引力。促进有性繁殖可以提高果实和种子的产量。抑制这一过程可以提高蔬菜产量。其他可能的操作包括利用雄性不育基因产生杂交种子，产生无核果实，以及促进自体受精。有性繁殖的一个重要步骤是花中含有雄性精子的花粉和含有雌性卵子的部分之间的相互作用。这种相互作用很大程度上是由花粉表面的分子启动的。花粉被层含有水不溶的脂类和半水溶蛋白质为主要成分。这些脂类和蛋白质来自包围成熟花粉的亲本细胞中的亚细胞颗粒。加州大学河滨分校的Anthony Huang教授的实验室将在拟南芥中研究这些亚细胞颗粒，拟南芥是卷心菜家族的模式植物。这些研究将着重于脂肪和蛋白质成分的选择性降解和保留，它们向花粉表面的运输和沉积，以及它们在授粉和受精过程中的作用。缺乏脂质和蛋白质的拟南芥突变体将被用来剖析这一亲本到花粉的途径。这一结果将揭示亲本细胞控制花粉成熟的机制，特别是对花粉毛形成的控制。他们还将确定花粉被层中丰富的脂类和蛋白质在授粉、花粉萌发和花粉管穿透柱头方面的功能。

Sexual reproduction in plants is a dynamic process, and its mechanism and control are complicated. Research into the molecular basis of flowering and fruiting is intellectually intriguing as well as practical in agriculture. Promoting sexual reproduction could enhance the yield of fruits and seeds. Suppressing the process could increase the yield of vegetable produce. Other possible manipulations include utilizing male sterile genes to produce hybrid seeds, generating seedless fruits, and promoting self fertilization. A major step in sexual reproduction is the interaction between the male sperm-containing pollen and the female egg-containing part in the flowers. This interaction is initiated largely by the molecules on the pollen surface. The pollen coat contains water-insoluble lipids and semi-water-soluble proteins as the major constituents. These lipids and proteins originate from subcellular particles in the parental cells enclosing the maturing pollen. The laboratory of Professor Anthony Huang at the University of California at Riverside will study these subcellular particles in Arabidopsis, a model plant of the cabbage family. The studies will emphasize the lipid and protein constituents in terms of their selective degradation and retention, their transport to and deposition on the pollen surface, and their function in the pollination and fertilization process. Arabidopsis mutants deficient in the lipids and proteins will be employed to dissect this parent-to-pollen pathway. The results will delineate the mechanism of the control that the parental cells have over pollen maturation, especially on the pollen coat formation. They will also define the functions of the abundant lipids and proteins in the pollen coat in pollination, pollen germination, and tube penetration into the stigma.