Abiotie stresses including potassium deficiency are limitingfactors for increasing rice yield.Nine rice genotypes(Oryza Sativa L.,indica)differing in sensitivity to low Kstress selected from 200 volume-solution screen...Abiotie stresses including potassium deficiency are limitingfactors for increasing rice yield.Nine rice genotypes(Oryza Sativa L.,indica)differing in sensitivity to low Kstress selected from 200 volume-solution screening wereused in this study to examine accumulation and transloca-tion ofK.The powdery-muddy paddy soil tested contained 30.6mg·kgavailable K(1 N NHAcO extracted),1.92%展开更多
A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanc...A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanced rice vegetative growth and increased grain yield and IKUE under low potassium. Addition of higher rate of NaCl had a negative effect on the growth of the K-efficient rice genotype, but did not for the K-inefficient genotype. Under low-K stress, higher NaCl decreased IKUE of the K-efficient rice genotype but increased IKUE for the K-inefficient genotype. At tillering stage and under low-K stress, adding NaCl increased K and Na contents and decreased the ratio of K/Na for both genotypes. At harvesting stage under low-K stress, adding NaCl increased K and Na contents and K/Na ratio for the K-efficient genotype but decreased the K/Na ratio for the K-inefficient genotype. The accumulated Na was mostly deposited in the roots and sheaths. At tillering stage, the K and Na contents and the K/Na ratios in different parts for both genotypes decreased in the following sequence: K+ in sheaths > K+ in blades > K+ in roots; Na+ in roots > Na+ in sheaths > Na+ in blades; and K/Na in sheaths 》 K/Na in roots. The K-efficient genotype had a lower K/Na ratio in roots and sheaths than the K-inefficient genotype under low-K stress. At harvesting stage, K and Na contents in grains were not affected, whereas K/Na ratio in the rice straws was increased for the K-efficient genotype but decreased for the K-inefficient genotype by Na addition. However, this was not the case under K sufficient condition.展开更多
Spatiotemporal regulation of gene expression by polycomb repressive complex 2(PRc2)is critical for animal and plant development.The Arabidopsis fertilization independent seed(FIS)-PRC2 complex functions specifically d...Spatiotemporal regulation of gene expression by polycomb repressive complex 2(PRc2)is critical for animal and plant development.The Arabidopsis fertilization independent seed(FIS)-PRC2 complex functions specifically during plant reproduction from gametogenesis to seed development.After a double fertilization event,triploid endosperm proliferates early,followed by the growth of a diploid embryo,which replaces the endosperm in Arabidopsis and many dicots.Key genes critical for endosperm proliferation such as IKkU2 and MINI3 are activated after fertilization.Here we report that two MADS-box AGAMOUS-LIKE(AGL)proteins associate with the key endosperm proliferation loci and recruit the FIS-PRC2 repressive complex at 4-5 days after pollination(DAP).Interestingly,AGL9 and AGL15 only accumulate toward the end of endosperm proliferation at 4-5 DAP and promote the deposition of H3K27me3 marks at key endosperm proliferation loci.Disruption of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm proliferation and cellularization.Genome-wide analysis with cleavage Under Targets and tagmentation(CUT&Tag)sequencing and RNA sequencing revealed the landscape of endosperm H3K27me3 marks and gene expression profiles in Col-0 and agl9 agl15.CUT&Tag qPCR also demonstrated the occupancy of the two MADS-box proteins and FIS-PRC2 on a few representative target loci.Our studies suggest that MADS-box proteins could potentially recruit PRc2 to regulate many other developmental processes in plants or even in fungi and animals.展开更多
Evolution is driven by various mechanisms.A directional increase in the embryo to endosperm ratio is an evolutionary trend within the angiosperms.The endosperm constitutes a major portion of the seed volume in Poales ...Evolution is driven by various mechanisms.A directional increase in the embryo to endosperm ratio is an evolutionary trend within the angiosperms.The endosperm constitutes a major portion of the seed volume in Poales and some dicots.However,in other dicots such as Arabidopsis and soybean,the endosperm proliferates early,followed by embryo growth to replace the endosperm.The Arabidopsis leucine-rich repeat receptor protein kinase AtHAIKU2(AtIKU2)is a key regulator of early endosperm proliferation.In this study,we found that IKU2s from Brachypodium,rice,and soybean can complement the abnormal seed developmental phenotype of Atiku2,while AtIKU2 also rescues the defective endosperm proliferation in the Brachypodium BdIKU2 knockout mutant seeds.AtIKU2 and soybean GmIKU2 are actively expressed a few days after fertilization.Thereafter,expression of AtIKU2 is suppressed by the FIS-PRC2 complex-mediated H3K27me3.The soybean GmIKU2 locus is also enriched with H3K27me3 marks.The histone methyltransferase AtMEA is unique to Brassicaceae,but one GmSWN in soybean plays a similar role in seed development as AtMEA.By contrast,the BdIKU2 and rice OsIKU2 loci are continuously expressed and are devoid of H3K27me3 marks.Taken together,these results suggest that IKU2 genes retain an ancestral function,but the duration of their expression that is controlled by PRC2-mediated epigenetic silencing contributes to silenced or persistent endosperm proliferation in different species.Our study reveals an epigenetic mechanism that drives the development of vastly different seed ontogenies.展开更多
文摘Abiotie stresses including potassium deficiency are limitingfactors for increasing rice yield.Nine rice genotypes(Oryza Sativa L.,indica)differing in sensitivity to low Kstress selected from 200 volume-solution screening wereused in this study to examine accumulation and transloca-tion ofK.The powdery-muddy paddy soil tested contained 30.6mg·kgavailable K(1 N NHAcO extracted),1.92%
基金Project (No. 315200) supported by the the Outstanding Young Scientist Grant of Natural Science Foundationof Zhejiang Pr
文摘A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanced rice vegetative growth and increased grain yield and IKUE under low potassium. Addition of higher rate of NaCl had a negative effect on the growth of the K-efficient rice genotype, but did not for the K-inefficient genotype. Under low-K stress, higher NaCl decreased IKUE of the K-efficient rice genotype but increased IKUE for the K-inefficient genotype. At tillering stage and under low-K stress, adding NaCl increased K and Na contents and decreased the ratio of K/Na for both genotypes. At harvesting stage under low-K stress, adding NaCl increased K and Na contents and K/Na ratio for the K-efficient genotype but decreased the K/Na ratio for the K-inefficient genotype. The accumulated Na was mostly deposited in the roots and sheaths. At tillering stage, the K and Na contents and the K/Na ratios in different parts for both genotypes decreased in the following sequence: K+ in sheaths > K+ in blades > K+ in roots; Na+ in roots > Na+ in sheaths > Na+ in blades; and K/Na in sheaths 》 K/Na in roots. The K-efficient genotype had a lower K/Na ratio in roots and sheaths than the K-inefficient genotype under low-K stress. At harvesting stage, K and Na contents in grains were not affected, whereas K/Na ratio in the rice straws was increased for the K-efficient genotype but decreased for the K-inefficient genotype by Na addition. However, this was not the case under K sufficient condition.
基金a grant from National Science Foundation IOS-1933291(M.N.).
文摘Spatiotemporal regulation of gene expression by polycomb repressive complex 2(PRc2)is critical for animal and plant development.The Arabidopsis fertilization independent seed(FIS)-PRC2 complex functions specifically during plant reproduction from gametogenesis to seed development.After a double fertilization event,triploid endosperm proliferates early,followed by the growth of a diploid embryo,which replaces the endosperm in Arabidopsis and many dicots.Key genes critical for endosperm proliferation such as IKkU2 and MINI3 are activated after fertilization.Here we report that two MADS-box AGAMOUS-LIKE(AGL)proteins associate with the key endosperm proliferation loci and recruit the FIS-PRC2 repressive complex at 4-5 days after pollination(DAP).Interestingly,AGL9 and AGL15 only accumulate toward the end of endosperm proliferation at 4-5 DAP and promote the deposition of H3K27me3 marks at key endosperm proliferation loci.Disruption of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm proliferation and cellularization.Genome-wide analysis with cleavage Under Targets and tagmentation(CUT&Tag)sequencing and RNA sequencing revealed the landscape of endosperm H3K27me3 marks and gene expression profiles in Col-0 and agl9 agl15.CUT&Tag qPCR also demonstrated the occupancy of the two MADS-box proteins and FIS-PRC2 on a few representative target loci.Our studies suggest that MADS-box proteins could potentially recruit PRc2 to regulate many other developmental processes in plants or even in fungi and animals.
基金the National Natural Science Foundation of China(32071921 X.YZJ)National Key Research and Development Program 2021YFF1001203(D.J.Z)+1 种基金National Natural Science Foundation of China 31730008(X.S.Z.)National Science Foundation IOS-1933291(M.N.).
文摘Evolution is driven by various mechanisms.A directional increase in the embryo to endosperm ratio is an evolutionary trend within the angiosperms.The endosperm constitutes a major portion of the seed volume in Poales and some dicots.However,in other dicots such as Arabidopsis and soybean,the endosperm proliferates early,followed by embryo growth to replace the endosperm.The Arabidopsis leucine-rich repeat receptor protein kinase AtHAIKU2(AtIKU2)is a key regulator of early endosperm proliferation.In this study,we found that IKU2s from Brachypodium,rice,and soybean can complement the abnormal seed developmental phenotype of Atiku2,while AtIKU2 also rescues the defective endosperm proliferation in the Brachypodium BdIKU2 knockout mutant seeds.AtIKU2 and soybean GmIKU2 are actively expressed a few days after fertilization.Thereafter,expression of AtIKU2 is suppressed by the FIS-PRC2 complex-mediated H3K27me3.The soybean GmIKU2 locus is also enriched with H3K27me3 marks.The histone methyltransferase AtMEA is unique to Brassicaceae,but one GmSWN in soybean plays a similar role in seed development as AtMEA.By contrast,the BdIKU2 and rice OsIKU2 loci are continuously expressed and are devoid of H3K27me3 marks.Taken together,these results suggest that IKU2 genes retain an ancestral function,but the duration of their expression that is controlled by PRC2-mediated epigenetic silencing contributes to silenced or persistent endosperm proliferation in different species.Our study reveals an epigenetic mechanism that drives the development of vastly different seed ontogenies.
