Rice florets are subtended by two sterile lemmas,whose origin and biological functions have not been studied extensively.Here we demonstrate that two putative transcription factors,LAX PANICLE1(LAX1)and FRIZZY PANICLE...Rice florets are subtended by two sterile lemmas,whose origin and biological functions have not been studied extensively.Here we demonstrate that two putative transcription factors,LAX PANICLE1(LAX1)and FRIZZY PANICLE(FZP),synergistically control the development of sterile lemmas.Both LAX1 and FZP are previously known for their roles in panicle and floret development.Disruption of either LAX1 or FZP greatly reduces the number of floret development.We generated new lax1 mutants(lax1-c)using CRISPR/Cas9 gene editing technology.In addition to the expected lax panicle phenotypes,we noticed that a significant number of spikelets of lax1-c developed elongated sterile lemmas.Moreover,our characterization of lax1-RNAi plants also revealed sterile lemma phenotypes similar to lax1-c mutants.We isolated a weak allele of fzp(fzp-14)in a genetic screen for lax1–1 enhancers.The fzp-14 lax1–1 double mutants completely eliminated flower development.Interestingly,the isolated fzp-14 produced spikelets with elongated sterile lemmas.Furthermore,fzp-14 was haploid-insufficient in the lax1–1 background whereas fzp-14 heterozygous plants were indistinguishable from wild type plants.The lax1–1 fzp-14+/−also developed elongated sterile lemma as observed in lax1-c,lax1-RNAi,and fzp-14,suggesting that LAX1 and FZP synergistically control sterile lemma development.展开更多
A mutant of spikelet differentiation in rice called frizzle panicle (fzp) was discovered in the progeny of a cross between Oryza sativa ssp. indica cv. V20B and cv. Hua1B. The mutant ex-hibits normal plant morphology ...A mutant of spikelet differentiation in rice called frizzle panicle (fzp) was discovered in the progeny of a cross between Oryza sativa ssp. indica cv. V20B and cv. Hua1B. The mutant ex-hibits normal plant morphology but has apparently fewer tillers. The most striking change in fzp is that its spikelet differentiation is completely blocked, with unlimited subsequent rachis branches generated from the positions where spikelets normally develop in wild-type plants. Genetic analy-sis suggests that fzp is controlled by a single recessive gene, which is temporarily named fzp (t). Based on its mutant phenotype, fzp (t) represents a key gene controlling spikelet differentiation. Some F2 mutant plants derived from various genetic background appeared as the middle type? suggesting that the action of fzp (t) is influenced by the presence of redundant, modifier or interac-tive genes. By using simple sequence repeat (SSR) markers and bulked segregant analysis (BSA) method, fzp (t) gene was mapped in the terminal region of the long arm of chromosome 7, with RM172 and RM248 on one side, 3.2 cM and 6.4 cM from fzp (t), and RM18 and RM234 on the other side, 23.1 cM and 26.3 cM from fzp(t), respectively. These results will facilitate the positional cloning and function studies of the gene.展开更多
基金supported by the National Transgenic Research Program of China(2016ZX08010002)
文摘Rice florets are subtended by two sterile lemmas,whose origin and biological functions have not been studied extensively.Here we demonstrate that two putative transcription factors,LAX PANICLE1(LAX1)and FRIZZY PANICLE(FZP),synergistically control the development of sterile lemmas.Both LAX1 and FZP are previously known for their roles in panicle and floret development.Disruption of either LAX1 or FZP greatly reduces the number of floret development.We generated new lax1 mutants(lax1-c)using CRISPR/Cas9 gene editing technology.In addition to the expected lax panicle phenotypes,we noticed that a significant number of spikelets of lax1-c developed elongated sterile lemmas.Moreover,our characterization of lax1-RNAi plants also revealed sterile lemma phenotypes similar to lax1-c mutants.We isolated a weak allele of fzp(fzp-14)in a genetic screen for lax1–1 enhancers.The fzp-14 lax1–1 double mutants completely eliminated flower development.Interestingly,the isolated fzp-14 produced spikelets with elongated sterile lemmas.Furthermore,fzp-14 was haploid-insufficient in the lax1–1 background whereas fzp-14 heterozygous plants were indistinguishable from wild type plants.The lax1–1 fzp-14+/−also developed elongated sterile lemma as observed in lax1-c,lax1-RNAi,and fzp-14,suggesting that LAX1 and FZP synergistically control sterile lemma development.
基金supported by the Tenth Five-year National High Technology Research and Development Program of China(863 2001AA222271)partly by the State Key Basic Research and Development Program of China(G1999011602).
文摘A mutant of spikelet differentiation in rice called frizzle panicle (fzp) was discovered in the progeny of a cross between Oryza sativa ssp. indica cv. V20B and cv. Hua1B. The mutant ex-hibits normal plant morphology but has apparently fewer tillers. The most striking change in fzp is that its spikelet differentiation is completely blocked, with unlimited subsequent rachis branches generated from the positions where spikelets normally develop in wild-type plants. Genetic analy-sis suggests that fzp is controlled by a single recessive gene, which is temporarily named fzp (t). Based on its mutant phenotype, fzp (t) represents a key gene controlling spikelet differentiation. Some F2 mutant plants derived from various genetic background appeared as the middle type? suggesting that the action of fzp (t) is influenced by the presence of redundant, modifier or interac-tive genes. By using simple sequence repeat (SSR) markers and bulked segregant analysis (BSA) method, fzp (t) gene was mapped in the terminal region of the long arm of chromosome 7, with RM172 and RM248 on one side, 3.2 cM and 6.4 cM from fzp (t), and RM18 and RM234 on the other side, 23.1 cM and 26.3 cM from fzp(t), respectively. These results will facilitate the positional cloning and function studies of the gene.
