title: Morphological and gene expression analysis under cool temperature conditions in rice anther development.
abstract: Cool temperature conditions are known to lead to pollen sterility in rice. Pollen sterility is an agriculturally important phenomenon because it imparts a large influence directly on rice yield. However, cool temperature stress tolerance varies among rice cultivars and avoidance of cool temperature stress is difficult by practical method of agriculture. In this study using two rice cultivars, Hitomebore (high tolerance) and Sasanishiki (low tolerance), we analyzed morphological features and gene expression profiles, under cool temperature stress, in anther development of rice. Hitomebore was given cool temperature stress (19 degrees C) at flowering stage, and showed 87.3% seed fertility. Meanwhile, the seed fertility decreased to 41.7% in the case of Sasanishiki. A transverse section of Hitomebore anther revealed that the degradation of the tapetum started at the uninucleate microspore stage, and the tapetum had completely vanished at mature stage. The tapetum provides nutrients for pollen development, and its degradation occurs at a late stage in pollen development. In contrast, degradation of the tapetum did not occur at the uninucleate microspore stage in Sasanishiki, and the tapetum was clearly intact at mature stage, suggesting that tapetum degradation is critical for accurate pollen development and cool temperature tolerance correlated with the degree of tapetum degeneration. In gene expression analysis of anther, 356 genes that showed different expression levels between two cultivars at cool temperatures were found. These genes will lead to understanding the mechanism of cool temperature stress response in rice pollen development and the identification of genes involved in accurate tapetum degradation.
authors.affiliation: Graduate School of Life Sciences, Tohoku University.
authors.forename: Susumu
authors.initials: S
authors.lastname: Oda
authors.forename: Fumi
authors.initials: F
authors.lastname: Kaneko
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yano
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Fujioka
authors.forename: Hiromi
authors.initials: H
authors.lastname: Masuko
authors.forename: Jong-In
authors.initials: JI
authors.lastname: Park
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Hamada
authors.forename: Makoto
authors.initials: M
authors.lastname: Endo
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Nagano
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nagamura
authors.forename: Makiko
authors.initials: M
authors.lastname: Kawagishi-Kobayashi
authors.forename: Keita
authors.initials: K
authors.lastname: Suwabe
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.forename: Masao
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D005298:Fertility; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007564:Japan; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D011058:Pollen / Q000502:physiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics / Q000302:isolation & purification; D012639:Seeds / Q000502:physiology; D013696:Temperature; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D018749:RNA, Plant