Small and round seed 5 gene encodes alpha-tubulin regulating seed cell elongation in rice.
Seed size is an important trait in determinant of rice seed quality and yield. In this study, we report a novel semi-dominant mutant Small and round seed 5 (Srs5) that encodes alpha-tubulin protein. Lemma cell length was reduced in Srs5 compared with that of the wild-type. Mutants defective in the G-protein alpha subunit (d1-1) and brassinosteroid receptor, BRI1 (d61-2) also exhibited short seed phenotypes, the former due to impaired cell numbers and the latter due to impaired cell length. Seeds of the double mutant of Srs5 and d61-2 were smaller than those of Srs5 or d61-2. Furthermore, SRS5 and BRI1 genes were highly expressed in Srs5 and d61-2 mutants. These data indicate that SRS5 independently regulates cell elongation of the brassinosteroid signal transduction pathway.
Faculty of Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
Shuhei
S
Segami
Institute of the Society for Techno-innovation of Agriculture, Forestry and Fisheries, 446-1 Ippaizuka, Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan ; Laboratory of Synaptic Plasticity and Connectivity RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Izumi
I
Kono
Institute of the Society for Techno-innovation of Agriculture, Forestry and Fisheries, 446-1 Ippaizuka, Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan ; National Institute of Agrobiological Science, 2-1-1 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
Tsuyu
T
Ando
National Institute of Agrobiological Science, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634 Japan.
Masahiro
M
Yano
Bioscience and Biotechnology Center, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8601, Japan.
Hidemi
H
Kitano
Faculty of Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
Kotaro
K
Miura
Faculty of Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan.
Yukimoto
Y
Iwasaki