Development of the "Third-Generation" Hybrid Rice in China / 基因组蛋白质组与生物信息学报·英文版

Rice is a major cereal crop for China. The development of the "three-line" hybrid rice system based on cytoplasmic male sterility in the 1970s (first-generation) and the "two-line" hybrid rice system based on photoperiod- and thermo-sensitive genic male-sterile lines (second-generation) in the 1980s has contributed significantly to rice yield increase and food security in China. Here we describe the development and implementation of the "third-generation" hybrid rice breeding system that is based on a transgenic approach to propagate and utilize stable recessive nuclear male sterile lines, and as such, the male sterile line and hybrid rice produced using such a system is non-transgenic. Such a system should overcome the intrinsic problems of the "first-generation" and "second-generation" hybrid rice systems and hold great promise to further boost production of hybrid rice and other crops.

UV-B-induced photomorphogenesis in Arabidopsis

Ultraviolet-B (UV-B) is a relatively minor component of sunlight, but can induce stress-related physiological processes or UV-B-specific photomorphogenic responses in plants. In the last decade, significant progress has been made in understanding the UV-B photomorphogenic pathway, including identification of the key components in the pathway, molecular characterization of UV-B photoreceptor and perception mechanism, and elucidation of the signal transduction mechanisms from the photoactivated UV-B receptor to downstream gene expression. This review summarizes the key players identified to date in the UV-B photomorphogenic pathway and their roles in mediating UV-B signal transduction.

Genomic basis for light control of plant development

Light is one of the key environmental signals regulating plant growth and development. Therefore, understanding the mechanisms by which light controls plant development has long been of great interest to plant biologists. Traditional genetic and molecular approaches have successfully identified key regulatory factors in light signaling, but recent genomic studies have revealed massive reprogramming of plant transcriptomes by light, identified binding sites across the entire genome of several pivotal transcription factors in light signaling, and discovered the involvement of epigenetic regulation in light-regulated gene expression. This review summarizes the key genomic work conducted in the last decade which provides new insights into light control of plant development.

The MYB transcription factor superfamily of Arabidopsis: expression analysis and phylogenetic comparison with the rice MYB family.

MYB proteins are a superfamily of transcription factors that play regulatory roles in developmental processes and defense responses in plants. We identified 198 genes in the MYB superfamily from an analysis of the complete Arabidopsis genome sequence, among them, 126 are R2R3-MYB, 5 are R1R2R3-MYB, 64 are MYB-related, and 3 atypical MYB genes. Here we report the expression profiles of 163 genes in the Arabidopsis MYB superfamily whose full-length open reading frames have been isolated. This analysis indicated that the expression for most of the Arabidopsis MYB genes were responsive to one or multiple types of hormone and stress treatments. A phylogenetic comparison of the members of this superfamily in Arabidopsis and rice suggested that the Arabidopsis MYB superfamily underwent a rapid expansion after its divergence from monocots but before its divergence from other dicots. It is likely that the MYB-related family was more ancient than the R2R3-MYB gene family, or had evolved more rapidly. Therefore, the MYB gene superfamily represents an excellent system for investigating the evolution of large and complex gene families in higher plants. Our comprehensive analysis of this largest transcription factor superfamily of Arabidopsis and rice may help elucidate the possible biological roles of the MYB genes in various aspects of flowering plants.