The microscopic investigation of the floral development of sweet cherry（Prunus avium L. cv. Hongdeng） from a warm winter climate（Shanghai） and cold winter climate（Tai＇an, Shandong Province, China） was conducted...The microscopic investigation of the floral development of sweet cherry（Prunus avium L. cv. Hongdeng） from a warm winter climate（Shanghai） and cold winter climate（Tai＇an, Shandong Province, China） was conducted to explore the reason of low fruit set. The effect of hydrogen cyanamide（HCN） on floral development under warm winter conditions was also investigated. Trees grown in Shanghai with insufficient chilling accumulation exhibited little difference in the progression of microspore development compared to trees in Tai＇an that accumulated adequate chilling, but showed substantial delays in ovule and embryo sac development. The growth of nucelli did not proceed beyond the macrospore mother cell and macrospore stages with abortion rates of 13, 15 and 45% by 6, 3 and 0 d before full bloom, respectively. These abnormalities in the ovule and embryo sac in the Shanghai-grown trees were eliminated by HCN application. These results suggest that chilling regulates the development of female floral organs in winter dormancy; therefore, insufficient chilling accumulation, causing abnormality of the female floral organs, restricts the cultivation of sweet cherry in warm winter regions. Interestingly, HCN application, which decreased the chilling requirements for Hongdeng, may be a potential strategy for sweet cherry cultivation in warm winter regions.展开更多
Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its tr...Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its translation. Small RNAs play regulatory roles in the growth and development process of plants at the core of gene regulatory networks, which has been widely studied and confirmed in sporophyte generation of plants. However, few researches have been conducted on small RNAs and gametophyte generation. It is reported that small RNAs play important roles in floral organ development, gametogenesis, fertilization, and early zygotic development of plants. In addition, various small RNAs also play roles in controlling genetic integrity, cell differentiation and functions during the sexual reproduction process of plants. However, most of the specific functions of small RNAs in the sexual reproduction process are unknown yet. This study mainly aimed to introduce small RNAs in plants, summarize the latest advances in researches of small RNAs and plant sexual reproduction, and make prospect on its future.展开更多
Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mec...Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mechanism of sex diff erentiation in fl ower development,we conducted the transcriptome profi les of male and female fl owers at early,metaphase and late developmental stages.Approximately 123,335 unigenes with a total length of 83,996 Mb and an average length of 168 bp were assembled.The unigenes were blasted into Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,GO databases.Homology analysis demonstrated that I.polycarpa and black cottonwood had the highest homology with the alignment of 92,871 sequences.This study identifi ed 80 groups of transcription factor families with a total of 1475 unigenes,mainly including MYB,WRKY,AP2 and bHLH transcription factor families.KEGG pathway analysis showed that the expression of numerous plant hormones(cytokinin,gibberellin and ethylene)and fl avonoid biosynthesis pathway were diff erent at various stages of female and male fl ower development.In addition,a number of unigenes associated with fl owering were identifi ed which were key genes associated with photoperiodic,vernalization,thermosensory,gibberellin,and autonomic pathways.The results show that I.polycarpa fl oral organ development was in accordance with the ABCDE model,in which the down-regulation of the B gene family might aff ect stamen fertility in late stages of female fl ower development.qRTPCR experiments validated that the expression patterns of 15 unigenes were consistent with those in RNA-seq results.The results highlight a central role for plant sex identifi cation in seedling production and a sex-determining mechanism for dioecious plants.In addition,the transcriptome data provided a theoretical basis for I.polycarpa genetic diversity analysis and molecular-assisted breeding.展开更多
基金supported by grants from the 948 Project of the Ministry of Agriculture of China(2013-Z23)the Shanghai Municipal Science Commission of China(10391900100)
文摘The microscopic investigation of the floral development of sweet cherry（Prunus avium L. cv. Hongdeng） from a warm winter climate（Shanghai） and cold winter climate（Tai＇an, Shandong Province, China） was conducted to explore the reason of low fruit set. The effect of hydrogen cyanamide（HCN） on floral development under warm winter conditions was also investigated. Trees grown in Shanghai with insufficient chilling accumulation exhibited little difference in the progression of microspore development compared to trees in Tai＇an that accumulated adequate chilling, but showed substantial delays in ovule and embryo sac development. The growth of nucelli did not proceed beyond the macrospore mother cell and macrospore stages with abortion rates of 13, 15 and 45% by 6, 3 and 0 d before full bloom, respectively. These abnormalities in the ovule and embryo sac in the Shanghai-grown trees were eliminated by HCN application. These results suggest that chilling regulates the development of female floral organs in winter dormancy; therefore, insufficient chilling accumulation, causing abnormality of the female floral organs, restricts the cultivation of sweet cherry in warm winter regions. Interestingly, HCN application, which decreased the chilling requirements for Hongdeng, may be a potential strategy for sweet cherry cultivation in warm winter regions.
基金Supported by National Natural Science Foundation of China(30971986)Specialized Research Fund for the Doctoral Program of Higher Education of China(20110182110013)Doctoral Fund of Southwestern University(SWU111016)~~
文摘Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its translation. Small RNAs play regulatory roles in the growth and development process of plants at the core of gene regulatory networks, which has been widely studied and confirmed in sporophyte generation of plants. However, few researches have been conducted on small RNAs and gametophyte generation. It is reported that small RNAs play important roles in floral organ development, gametogenesis, fertilization, and early zygotic development of plants. In addition, various small RNAs also play roles in controlling genetic integrity, cell differentiation and functions during the sexual reproduction process of plants. However, most of the specific functions of small RNAs in the sexual reproduction process are unknown yet. This study mainly aimed to introduce small RNAs in plants, summarize the latest advances in researches of small RNAs and plant sexual reproduction, and make prospect on its future.
文摘Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mechanism of sex diff erentiation in fl ower development,we conducted the transcriptome profi les of male and female fl owers at early,metaphase and late developmental stages.Approximately 123,335 unigenes with a total length of 83,996 Mb and an average length of 168 bp were assembled.The unigenes were blasted into Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,GO databases.Homology analysis demonstrated that I.polycarpa and black cottonwood had the highest homology with the alignment of 92,871 sequences.This study identifi ed 80 groups of transcription factor families with a total of 1475 unigenes,mainly including MYB,WRKY,AP2 and bHLH transcription factor families.KEGG pathway analysis showed that the expression of numerous plant hormones(cytokinin,gibberellin and ethylene)and fl avonoid biosynthesis pathway were diff erent at various stages of female and male fl ower development.In addition,a number of unigenes associated with fl owering were identifi ed which were key genes associated with photoperiodic,vernalization,thermosensory,gibberellin,and autonomic pathways.The results show that I.polycarpa fl oral organ development was in accordance with the ABCDE model,in which the down-regulation of the B gene family might aff ect stamen fertility in late stages of female fl ower development.qRTPCR experiments validated that the expression patterns of 15 unigenes were consistent with those in RNA-seq results.The results highlight a central role for plant sex identifi cation in seedling production and a sex-determining mechanism for dioecious plants.In addition,the transcriptome data provided a theoretical basis for I.polycarpa genetic diversity analysis and molecular-assisted breeding.
