Morphogenesis and molecular basis on naked seed rice, a novel homeotic mutation of OsMADS1 regulating transcript level of AP3 homologue in rice.
The floral organs are formed from floral meristem with a regular initiation pattern in angiosperm species. Flowers of naked seed rice (nsr) were characterized by the overdeveloped lemma and palea, the transformation of lodicules to palea-/lemma-like organs, the decreased number of stamens and occasionally extra pistils. Some nsr spikelets contained additional floral organs of four whorls and/or abnormal internal florets. The floral primordium of nsr spikelet is differentiated under an irregular pattern and an incomplete determination. And molecular analysis indicated that nsr was a novel homeotic mutation in OsMADS1, suggesting that OsMADS1 played a distinct role in regulating the differentiation pattern of floral primordium and in conferring the determination of flower meristem. The gain-of-function of OsMADS1 transgenic lines presented the transformation of outer glumes to lemma-/palea-like organs and no changes in length of lemma and palea, but loss-of-function of OsMADS1 transgenic lines displayed the overdeveloped lemma and palea. Both findings revealed that OsMADS1 played a role in specifying lemma and palea and acted as a repressor of overdevelopment of lemma and palea. Moreover, it was indicated that OsMADS1 upregulated the transcript level of AP3 homologue OsMADS16, using real-time PCR analysis on gain- and loss-of-function of OsMADS1 transgenic lines.
Chen
Zhi-Xiong
ZX
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, 310029, People's Republic of China.
Wu
Jian-Guo
JG
Ding
Wo-Na
WN
Chen
Han-Ming
HM
Wu
Ping
P
Shi
Chun-Hai
CH
D029681:Arabidopsis Proteins; D035264:Flowers / Q000254:growth & development* / Q000648:ultrastructure; D005801:Genes, Homeobox; D026161:MADS Domain Proteins; D008855:Microscopy, Electron, Scanning; D009024:Morphogenesis; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D034622:RNA Interference; D015854:Up-Regulation
C101342:APETALA 3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins