Dear Editor, Male reproductive development is an essential biological process for flowering plants and crucial for crop seed production.Formation of the male reproductive organ,the anther,involves a number of developmental events,including stamen meristem specification,generation of sporogenous cells and their differentiation into microspore mother cells (MMCs),meiosis,microspore (pollen) maturation,and pollination (Ma,2005).The formation of microspores and their development into mature pollen grains require cooperative interactions between gametophytic (microspores) and sporophytic (anther wall) cells,with the innermost cell layer,the tapetum,playing the most crucial role (Ma,2005).Tapetal cells undergo degeneration by programmed cell death (PCD).
Chonghui Ji Heying Li Libin Chen Min Xie Fengping Wang Yuanling Chen Yao-Guang Liu
Plant mutants are important bio-resources for crop breeding and gene functional studies. Conventional methods for generating mutant libraries by mutagenesis of seeds with physical or chemical agents are of low efficiency. Here, we developed a highly-efficient ethyl methanesulfonate (EMS) mutagenesis system based on suspension-cultured cells, with rice (Oryza sativa L.) as an example. We show that treatment of suspension-cultured tiny cell clusters with 0.4% EMS for 18-22h followed by differentiation and regeneration produced as high as 29.4% independent mutant lines with visible phenotypic variations, including a number of important agronomic traits such as grain size, panicle size, grain or panicle shape, tiller number and angle, heading date, male sterility, and disease sensitivity. No mosaic mutant was observed in the mutant lines tested. In this mutant library, we obtained a mutant with an abnormally elongated uppermost internode. Sequencing and functional analysis revealed that this is a new allelic mutant of eui (elongated uppermost internode) caused by two point mutations in the first exon of the EUI gene, representing a successful example of this mutagenesis system.
Yuan-Ling ChenHui-Lin LiangXing-Liang MaSu-Lin LouYong-Yao XieZhen-Lan LiuLe-Tian ChenYao-Guang Liu
Plant leaves play a significant role in photosynthesis.Normal chloroplast development is critical for plant growth and yield performance.Defect of the chlorophyll in chloroplasts may cause abnormal leaf colors,such as yellow,white,or stripe.Chloroplasts have their own genomes encoding for about 100 genes that are essential for plastid protein synthesis and photosynthesis(Kanno and Hirai,1993;
Qunyu ZhangDexing XueXiaoyu LiYunming LongXianjie ZengYaoguang Liu
