In Brassica napus L.(rapeseed),complete genic male sterility(GMS)plays an important role in the utilization of heterosis.Although microRNAs(miRNAs)play essential regulatory roles during bud development,knowledge of ho...In Brassica napus L.(rapeseed),complete genic male sterility(GMS)plays an important role in the utilization of heterosis.Although microRNAs(miRNAs)play essential regulatory roles during bud development,knowledge of how GMS is regulated by miRNAs in rapeseed is rather limited.In this study,we obtained a novel recessive GMS system,CN12AB.The sterile line CN12A has defects in tapetal diferentiation and degradation.llumina sequencing was employed to examine the expression of miRNAs in the buds of CN12A and the fertile line CN12B.We identifed 85 known miRNAs and 120 novel miRNAs that were expressed during rapeseed anther development.When comparing the expression levels of miRNAs between CN12A and CN12B,19 and 18 known miRNAs were found to be difrentially expressed in 0.5--1.0 mm buds and in 2.5--3.0 mm buds,respectively.Among these,the expression levels of 14 miRNAs were higher and the levels of 23 miRNAs were lower in CN12A compared with CN12B.The predicted target genes of these iferentially expressed miRNAS encode protein kinases,F-box domain-containing proteins,MADS-box family proteins,SBP-box gene family members,HD ZIP proteins,floral homeotic protein APETAL A 2(AP2)。and nuclear factor Y,subunit A.These targets have previously been reported to be involved in pollen development and male sterility,suggesting that miRNAs might act as regulators of GMS in rapeseed anthers.Furthermore,RT-qPCR data suggest that one of the dffrentially expressed miRNAs,bna-miR159,plays a role in tapetal differentiation by regulating the expression of transcription factor BnMYB101 and participates in tapetal degradation and infuences callose degradation by manipulating the expression of BnA6.These findings contibute to our understanding of the roles of miRNAs during anther development and the occurrence of GMS in rapeseed.展开更多
Increasing the planting density is an effective way to increase the yield of maize(Zea mays L.),although it can also aggravate ovary apical abortion-induced bald tips of the ears,which might,in turn,reduce the yield.W...Increasing the planting density is an effective way to increase the yield of maize(Zea mays L.),although it can also aggravate ovary apical abortion-induced bald tips of the ears,which might,in turn,reduce the yield.While the mechanism underlying the regulation of drought-related abortion in maize is well established,high planting density-related abortion in maize remains poorly understood.Therefore,the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density.This was achieved by evaluating the effects of four different plant densities(60000 plants ha^(–1)(60 k),90 k,120 k,and 150 k)on plant traits related to plant architecture,the plant ear,flowering time,and silk development in two inbred lines(Zheng58 and PH4CV)and two hybrid lines(Zhengdan958 and Xianyu335).The phenotypes of both inbred and hybrid plants were observed under different planting density treatments,and the high planting density was found to increase the phenotypic performance values of the evaluated traits.The anthesis–silking interval(ASI)was extended,and the amount of the silk extruded from husks was reduced upon increasing the planting density.Delayed silk emergence resulted in asynchronous flowering and ear bald tips.Observations of the silk cells revealed that the silk cells became smaller as planting density increased.The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism.These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.展开更多
基金This project was supported by the National Key Research Program of China(2018YFD0100500)the Major Projects for New Varieties of Genetically Modified Organisms,China(2018ZX0801109B)the Agricultural Science and Technology Innovation Project of Gansu Academy of Agricultural Sciences,China(2018GAAS04).
文摘In Brassica napus L.(rapeseed),complete genic male sterility(GMS)plays an important role in the utilization of heterosis.Although microRNAs(miRNAs)play essential regulatory roles during bud development,knowledge of how GMS is regulated by miRNAs in rapeseed is rather limited.In this study,we obtained a novel recessive GMS system,CN12AB.The sterile line CN12A has defects in tapetal diferentiation and degradation.llumina sequencing was employed to examine the expression of miRNAs in the buds of CN12A and the fertile line CN12B.We identifed 85 known miRNAs and 120 novel miRNAs that were expressed during rapeseed anther development.When comparing the expression levels of miRNAs between CN12A and CN12B,19 and 18 known miRNAs were found to be difrentially expressed in 0.5--1.0 mm buds and in 2.5--3.0 mm buds,respectively.Among these,the expression levels of 14 miRNAs were higher and the levels of 23 miRNAs were lower in CN12A compared with CN12B.The predicted target genes of these iferentially expressed miRNAS encode protein kinases,F-box domain-containing proteins,MADS-box family proteins,SBP-box gene family members,HD ZIP proteins,floral homeotic protein APETAL A 2(AP2)。and nuclear factor Y,subunit A.These targets have previously been reported to be involved in pollen development and male sterility,suggesting that miRNAs might act as regulators of GMS in rapeseed anthers.Furthermore,RT-qPCR data suggest that one of the dffrentially expressed miRNAs,bna-miR159,plays a role in tapetal differentiation by regulating the expression of transcription factor BnMYB101 and participates in tapetal degradation and infuences callose degradation by manipulating the expression of BnA6.These findings contibute to our understanding of the roles of miRNAs during anther development and the occurrence of GMS in rapeseed.
基金supported by the National Key R&D Program of China(2016YFD0101002)the National Natural Science Foundation of China(32072068)the Central Public-interest Scientific Institution Basal Research Fund,China(1610392021001)。
文摘Increasing the planting density is an effective way to increase the yield of maize(Zea mays L.),although it can also aggravate ovary apical abortion-induced bald tips of the ears,which might,in turn,reduce the yield.While the mechanism underlying the regulation of drought-related abortion in maize is well established,high planting density-related abortion in maize remains poorly understood.Therefore,the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density.This was achieved by evaluating the effects of four different plant densities(60000 plants ha^(–1)(60 k),90 k,120 k,and 150 k)on plant traits related to plant architecture,the plant ear,flowering time,and silk development in two inbred lines(Zheng58 and PH4CV)and two hybrid lines(Zhengdan958 and Xianyu335).The phenotypes of both inbred and hybrid plants were observed under different planting density treatments,and the high planting density was found to increase the phenotypic performance values of the evaluated traits.The anthesis–silking interval(ASI)was extended,and the amount of the silk extruded from husks was reduced upon increasing the planting density.Delayed silk emergence resulted in asynchronous flowering and ear bald tips.Observations of the silk cells revealed that the silk cells became smaller as planting density increased.The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism.These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.
