Enclosed stigma contributes to higher spikelet fertility for rice(Oryza sativa L.) subjected to heat stress
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摘要
With global warming, rice plants may be subjected to heat stress more regularly during the heatsensitive flowering stage, causing spikelet sterility and grain yield loss.Stigma exsertion is considered to increase pollen reception and promote female reproductive success.The aim of this study was to investigate the role of stigma exsertion on spikelet fertility at high temperatures.Five rice cultivars(Liangyoupeijiu, Shanyou 63, Huanghuazhan, Nagina 22, and IR64) with differing degrees of stigma exsertion were cultivated and exposed to high temperature at anthesis.Heat-tolerant cultivars did not always show a high percentage of spikelets with exserted stigmas, and vice versa.Irrespective of the presence of more pollen grains on exserted stigmas, spikelets with exserted stigmas did not show greater spikelet fertility than spikelets with fewer exserted stigmas or hidden stigmas under heat stress.GA3 application augmented the percentage of spikelets with exserted stigmas; however, it did not increase spikelet fertility under heat stress.Spikelet fertility of whole panicles was negatively correlated with the percentage of spikelets with exserted stigmas, but positively with that with hidden stigmas.Viability of the hidden stigmas was less reduced than that of exserted stigmas under heat stress, suggesting that hidden stigmas have an advantage in maintaining viability.Heat stress delayed anther dehiscence and reduced the viabilities of both exserted stigmas and pollens, thereby causing low spikelet fertility.Together, these results suggest that high spikelet fertility does not depend on stigma exsertion and that enclosed stigma generally contributes to higher spikelet fertility and heat tolerance under high-temperature conditions during flowering in rice.
With global warming, rice plants may be subjected to heat stress more regularly during the heatsensitive flowering stage, causing spikelet sterility and grain yield loss.Stigma exsertion is considered to increase pollen reception and promote female reproductive success.The aim of this study was to investigate the role of stigma exsertion on spikelet fertility at high temperatures.Five rice cultivars(Liangyoupeijiu, Shanyou 63, Huanghuazhan, Nagina 22, and IR64) with differing degrees of stigma exsertion were cultivated and exposed to high temperature at anthesis.Heat-tolerant cultivars did not always show a high percentage of spikelets with exserted stigmas, and vice versa.Irrespective of the presence of more pollen grains on exserted stigmas, spikelets with exserted stigmas did not show greater spikelet fertility than spikelets with fewer exserted stigmas or hidden stigmas under heat stress.GA3 application augmented the percentage of spikelets with exserted stigmas; however, it did not increase spikelet fertility under heat stress.Spikelet fertility of whole panicles was negatively correlated with the percentage of spikelets with exserted stigmas, but positively with that with hidden stigmas.Viability of the hidden stigmas was less reduced than that of exserted stigmas under heat stress, suggesting that hidden stigmas have an advantage in maintaining viability.Heat stress delayed anther dehiscence and reduced the viabilities of both exserted stigmas and pollens, thereby causing low spikelet fertility.Together, these results suggest that high spikelet fertility does not depend on stigma exsertion and that enclosed stigma generally contributes to higher spikelet fertility and heat tolerance under high-temperature conditions during flowering in rice.
With global warming, rice plants may be subjected to heat stress more regularly during the heatsensitive flowering stage, causing spikelet sterility and grain yield loss.Stigma exsertion is considered to increase pollen reception and promote female reproductive success.The aim of this study was to investigate the role of stigma exsertion on spikelet fertility at high temperatures.Five rice cultivars(Liangyoupeijiu, Shanyou 63, Huanghuazhan, Nagina 22, and IR64) with differing degrees of stigma exsertion were cultivated and exposed to high temperature at anthesis.Heat-tolerant cultivars did not always show a high percentage of spikelets with exserted stigmas, and vice versa.Irrespective of the presence of more pollen grains on exserted stigmas, spikelets with exserted stigmas did not show greater spikelet fertility than spikelets with fewer exserted stigmas or hidden stigmas under heat stress.GA3 application augmented the percentage of spikelets with exserted stigmas; however, it did not increase spikelet fertility under heat stress.Spikelet fertility of whole panicles was negatively correlated with the percentage of spikelets with exserted stigmas, but positively with that with hidden stigmas.Viability of the hidden stigmas was less reduced than that of exserted stigmas under heat stress, suggesting that hidden stigmas have an advantage in maintaining viability.Heat stress delayed anther dehiscence and reduced the viabilities of both exserted stigmas and pollens, thereby causing low spikelet fertility.Together, these results suggest that high spikelet fertility does not depend on stigma exsertion and that enclosed stigma generally contributes to higher spikelet fertility and heat tolerance under high-temperature conditions during flowering in rice.
引文
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[2]S.Fahad,S.Hussain,S.Saud,S.Hassan,M.Tanveer,M.Z.Ihsan,A.N.Shah,A.Ullah,Nasrullah,F.Khan,S.Ullah,H.Alharby,W.Nasim,C.Wu,J.Huang,A combined application of biochar and phosphorus alleviates heat-induced adversities on physiological,agronomical and quality attributes of rice,Plant Physiol.Biochem.103(2016)191-198.
[3]S.Das,P.Krishnan,M.Nayak,B.Ramakrishnan,High temperature stress effects on pollens of rice(Oryza sativa L.)genotypes,Environ.Exp.Bot.101(2014)36-46.
[4]T.Matsui,K.Omasa,T.Horie,Mechanism of anther dehiscence in rice(Oryza sativa L.),Ann.Bot.84(1999)501-506.
[5]T.Matsui,H.Kagata,Characteristics of floral organs related to reliable self-pollination in rice(Oryza sativa L.),Ann.Bot.91(2003)473-477.
[6]A.F.Edlund,R.Swanson,D.Preuss,Pollen and stigma structure and function:the role of diversity in pollination,Plant Cell 16(2004)S84-S97.
[7]K.Kobayashi,T.Matsui,Y.Murata,M.Yamamoto,Percentage of dehisced thecae and length of dehiscence control pollination stability of rice cultivars at high temperatures,Plant Prot.Sci.14(2011)89-95.
[8]P.V.V.Prasad,K.J.Boote,L.H.Allen,J.E.Sheehy,J.M.G.Thomas,Species,ecotype and cultivar differences in spikelet fertility and harvest index of rice in response to high temperature stress,Field Crop Res.95(2006)398-411.
[9]Z.A.Wilson,J.Song,B.Taylor,C.Yang,The final split:the regulation of anther dehiscence,J.Exp.Bot.62(2011)1633-1649.
[10]T.Matsui,K.Omasa,Rice(Oryza sativa L.)cultivars tolerant to high temperature at flowering:anther characteristics,Ann.Bot.89(2002)683-687.
[11]C.L.Yan,J.B.Wang,R.Q.Li,Effect of heat stress on calcium ultrastructural distribution in pepper anther,Environ.Exp.Bot.48(2002)161-168.
[12]N.Firon,R.Shaked,M.Peet,D.Pharr,E.Zamski,K.Rosenfeld,L.Althan,E.Pressman,Pollen grains of heat tolerant tomato cultivars retain higher carbohydrate concentration under heat stress conditions,Sci.Hortic.109(2006)212-217.
[13]T.Sakata,T.Oshino,S.Miura,M.Tomabechi,Y.Tsunaga,N.Higashitani,Y.Miyazawa,H.Takahashi,M.Watanabe,A.Higashitani,Auxins reverse plant male sterility caused by high temperatures,Proc.Natl.Acad.Sci.U.S.A.107(2010)8569-8574.
[14]K.Kobayashi,T.Matsui,Y.Murata,M.Yamamoto,Percentage of dehisced thecae and length of dehiscence control pollination stability of rice cultivarsat high temperatures,Plant Prot.Sci.14(2011)89-95.
[15]C.Zhang,N.Tateishi,K.Tanabe,Pollen density on the stigma affects endogenous gibberellin metabolism,seed and fruit set,and fruit quality in Pyrus pyrifolia,J.Exp.Bot.61(2010)4291-4302.
[16]D.J.Mackill,W.R.Coffman,J.N.Rutger,Pollen shedding and combining ability for high temperature tolerance in rice,Crop Sci.22(1982)730-733.
[17]V.Devasirvatham,P.M.Gaur,N.Mallikarjuna,T.N.Raju,R.M.Trethowan,D.K.Y.Tan,Reproductive biology of chickpea response to heat stress in the field is associated with the performance in controlled environments,Field Crop Res.142(2013)9-19.
[18]L.Tong,T.Yoshida,Can hot-water emasculation be applied to artificial hybridization of indica-type Cambodian rice?Plant Prot.Sci.11(2008)132-133.
[19]R.P.Xiao,J.Y.Li,X.Yao,X.W.Zhang,M.Wen,Y.Q.Tang,Flowering characteristics of Japonica rice male sterile lines adaptive to high temperature and summer drought,Agric.Sci.Technol.16(2015)1621-1627.
[20]C.Yin,P.Li,G.Gao,Q.Zhang,L.Luo,Y.He,QTL analysis of percentage of exserted stigma in rice,Mol.Plant Breed.12(2014)43-49.
[21]C.R.Elsy,M.Rangaswamy,K.N.Ganesan,Significance of stigma exsertion in enhancing outcrossing in male sterile rice lines,Int.Rice Res.Notes 23(2012)24-25.
[22]Y.B.Xu,Z.T.Shen,Receptivity of exserted stigmas,Int.Rice Res.Newslett.13(1988)7-8.
[23]W.G.Yan,Y.Li,H.A.Agrama,D.Luo,F.Gao,X.Lu,G.Ren,Association mapping of stigma and spikelet characteristics in rice(Oryza sativa L.),Mol.Breed.24(2009)277-292.
[24]N.Ercan,M.Akilli,Reasons for parthenocarpy and the effects of various hormone treatments on fruit set in pepino(Solarium muricatum Ait.),Sci.Hortic.66(1996)141-147.
[25]B.Y.Xu,Z.T.Shen,Z.N.Yang,C.S.Ying,Study on improving percentage of cross pollination in rice:analysis on variation of stigma exsertion in Oryza stativa L,J.Zhejiang Univ.12(1986)359-368(in Chinese with English abstract).
[26]R.Wassmann,S.V.K.Jagadish,S.B.Peng,K.Sumfleth,Y.Hosen,B.O.Sander,Rice production and global climate change:scope for adaptation and mitigation activities,in:R.Wassmann(Ed.),Proceedings of the Workshop on Advanced Technologies of Rice Production for Coping With Climate Change:"No Regret"Options for Adaptation and Mitigation and their Potential Uptake,IRRI Limited Proceedings No.16,International Rice Research Institute,Los Banos,Philippine 2010,pp.67-73.
[27]X.H.Tian,T.Matsui,S.H.Li,M.Yoshimoto,K.Kobayasi,T.Hasegawa,Heat-induced floret sterility of hybrid rice(Oryza sativa L.)cultivars under humid and low wind conditions in the field of Jianghan basin,China,Plant Prot.Sci.13(2010)243-251.
[28]C.Wu,K.Cui,W.Wang,Q.Li,S.Fahad,Q.Hu,J.Huang,L.Nie,S.Peng,Heat-induced phytohormone changes are associated with disrupted early reproductive development and reduced yield in rice,Sci.Rep.6(2016)34978.
[29]X.S.Du,H.X.Qi,Progress on the stigma exsertion in rice,Hubei Agric.Sci.54(2015)3841-3843(in Chinese with English abstract).
[30]C.Wu,K.Cui,W.Wang,Q.Li,S.Fahad,Q.Hu,J.Huang,L.Nie,P.K.Mohapatra,S.Peng,Heat-induced cytokinin transportation and degradation are associated with reduced panicle cytokinin expression and fewer spikelets per panicle in rice,Front.Plant Sci.8(2017)371.
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