Comprehensive transcriptome analysis of phytohormone biosynthesis and signaling genes in microspore/pollen and tapetum of rice.
To investigate the involvement of phytohormones during rice microspore/pollen (MS/POL) development, endogenous levels of IAA, gibberellins (GAs), cytokinins (CKs) and abscisic acid (ABA) in the mature anther were analyzed. We also analyzed the global expression profiles of genes related to seven phytohormones, namely auxin, GAs, CKs, brassinosteroids, ethylene, ABA and jasmonic acids, in MS/POL and tapetum (TAP) using a 44K microarray combined with a laser microdissection technique (LM-array analysis). IAA and GA(4) accumulated in a much higher amount in the mature anther compared with the other tissues, while CKs and ABA did not. LM-array analysis revealed that sets of genes required for IAA and GA synthesis were coordinately expressed during the later stages of MS/POL development, suggesting that these genes are responsible for the massive accumulation of IAA and GA(4) in the mature anther. In contrast, genes for GA signaling were preferentially expressed during the early developmental stages of MS/POL and throughout TAP development, while their expression was down-regulated at the later stages of MS/POL development. In the case of auxin signaling genes, such mirror-imaged expression observed in GA synthesis and signaling genes was not observed. IAA receptor genes were mostly expressed during the late stages of MS/POL development, and various sets of AUX/IAA and ARF genes were expressed during the different stages of MS/POL or TAP development. Such cell type-specific expression profiles of phytohormone biosynthesis and signaling genes demonstrate the validity and importance of analyzing the expression of phytohormone-related genes in individual cell types independently of other cells/tissues.
Hirano
Ko
K
Bioscience and Biotechnology Center, Nagoya University, Nagoya, 464-8601 Japan.
Aya
Koichiro
K
Hobo
Tokunori
T
Sakakibara
Hitoshi
H
Kojima
Mikiko
M
Shim
Rosalyn Angeles
RA
Hasegawa
Yasuko
Y
Ueguchi-Tanaka
Miyako
M
Matsuoka
Makoto
M
D016000:Cluster Analysis; D005718:Gametogenesis / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018745:Genome, Plant; D007834:Lasers; D042282:Microdissection / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D012275:Oryza / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D010937:Plant Growth Regulators / Q000096:biosynthesis / Q000235:genetics*; D011058:Pollen / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics; D016415:Sequence Alignment
D010937:Plant Growth Regulators; D018749:RNA, Plant