拟南芥生物钟双突变体lhycca1营养生长时相转变
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摘要
高等植物生长发育阶段可分为营养生长和生殖生长2个阶段,其中营养生长阶段中只有通过营养生长时相转变方可进入生殖生长阶段。营养生长时相转变(vegetative phase change,VPC)是植物从幼龄期(juvenile stage)到成熟期(adult phase)的转变,受到基因表达的调控。生物钟(circadian clock)相关基因LHY和CCA1单独作用延迟VPC的发生,这2个基因的共同作用下VPC是否受到影响尚未见报道。本研究以拟南芥(Arabidopsisthaliana)为研究对象,通过形态和茎尖分生组织(shoot apical meristem,SAM)解剖结构观察及调控因子miR156和靶基因SPL3的表达变化,分析LHY和CCA12个基因在VPC过程中的作用。结果表明:双突变体lhycca1生长周期为15d,莲座叶第5片时(第10天)出现远轴面表皮毛,此时叶基角和叶长宽比增大且茎尖分生组织凸起明显,miR156和SPL3的表达水平在植物生长发育阶段呈负相关变化。而野生型生长周期为20 d,莲座叶第6片(第15天)时才出现远轴面表皮毛、叶长宽、叶基角、SAM、miR156和SPL3的变化。这些结果说明在LHY和CCA1的共同作用下,VPC提前发生,LHY和CCA1 2个基因参与VPC的调控。
Developmental phase of higher plant is composed of two stages: vegetative growth and reproductive growth.Only after the phase transition through vegetative growth does plant go through further reproductive growth. The transition from the juvenile stage to the adult phase in plants is termed vegetative phase change(VPC), which is regulated by genes. Circadian clock-related genes LHY and CCA1 delay the occurrence of VPC by oneself, but the combined effects of these genes on VPC are not clear. Here, a double mutant lhycca1 of Arabidopsis thaliana was used to investigate the characters of VPC through the observation of plant morphology and anatomical structure of shoot tip meristem(shoot apical meristem, SAM). The expression of molecular regulatory factor miR156 and its target gene SPL3 in VPC were also analyzed. Our results showed that the growth cycle of the lhycca1 double mutant lasted for 15 d. The onset of abaxial trichomes was on the fifth rosette leaf(the 10~(th) day). Meanwhile, the base angle and the length: width ratio of leaves increased dramatically, and the shoot tip meristem bulged obviously. During growth and development, the expression levels of miR156 and SPL3 was negatively correlated. By contrast, the growth cycle of the wild-type was about 20 d, with the changes of the abaxial trichomes, length: width ratio of leaves, leaf base angle, SAM, miR156 and SPL3 on the sixth rosette leaf(the 15~(th) day). These results indicated that VPC in the lhycca1 double mutant occurred in advance under the combined effects of the two genes. LHY and CCA1 genes regulated VPC to some extent.
Developmental phase of higher plant is composed of two stages: vegetative growth and reproductive growth.Only after the phase transition through vegetative growth does plant go through further reproductive growth. The transition from the juvenile stage to the adult phase in plants is termed vegetative phase change(VPC), which is regulated by genes. Circadian clock-related genes LHY and CCA1 delay the occurrence of VPC by oneself, but the combined effects of these genes on VPC are not clear. Here, a double mutant lhycca1 of Arabidopsis thaliana was used to investigate the characters of VPC through the observation of plant morphology and anatomical structure of shoot tip meristem(shoot apical meristem, SAM). The expression of molecular regulatory factor miR156 and its target gene SPL3 in VPC were also analyzed. Our results showed that the growth cycle of the lhycca1 double mutant lasted for 15 d. The onset of abaxial trichomes was on the fifth rosette leaf(the 10~(th) day). Meanwhile, the base angle and the length: width ratio of leaves increased dramatically, and the shoot tip meristem bulged obviously. During growth and development, the expression levels of miR156 and SPL3 was negatively correlated. By contrast, the growth cycle of the wild-type was about 20 d, with the changes of the abaxial trichomes, length: width ratio of leaves, leaf base angle, SAM, miR156 and SPL3 on the sixth rosette leaf(the 15~(th) day). These results indicated that VPC in the lhycca1 double mutant occurred in advance under the combined effects of the two genes. LHY and CCA1 genes regulated VPC to some extent.
引文
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[9]Gou J Y,Felippes Felipe F,Liu C J,et al.Negative regulation of anthocyanin biosynthesis in Arabidopsis by a miR156-Targeted SPL transcription factor[J].Plant Cell,2011,23(4):1512-1522.
[10]Tsuyoshi M,Kay W,Yoshie H,et al.LHY and CCA1 are partially redundant genes required to maintain circadian rhythms in Arabidopsis[J].Developmental Cell,2002,2(5):629-641.
[11]Schaffer R,Landgraf J,Accerbi M,et al.Microarray analysis of diurnal and circadian-regulated genes in Arabidopsis[J].The Plant Cell,2001,13(1):113-123.
[12]Gendron Joshua M,Pruneda-Paz JoséL,Doherty Colleen J,et al.Arabidopsis circadian clock protein,TOC1,is a DNA-binding transcription factor[J].Proceedings of the National Academy of Sciences of the United States of America,2012,109(8):3167-3172.
[13]Alabadílaba Oyama T,Yanovsky M J,et al.Reciprocal regulation between TOC1 and LHY/CCA1 within the Arabidopsis circadian clock[J].Science,2001,293(5531):880-883.
[14]郭蕊.拟南芥生物节律钟相关基因LHY、CCA1和GI对其营养生长时相转变的作用[D].天津:天津农学院,2017.
[15]李和平.植物显微技术[M].2版.北京:科学出版社,2009:12-14,29,32-33.
[16]卢阳,龙鸿.拟南芥叶片数目变化突变体对营养生长时相转变的影响[J].植物学报,2015,50(3):331-337.
[17]Usami T,Horiguchi G,Yano S,et al.The more and smaller cells mutants of Arabidopsis thaliana identify novel roles for SQUAMOSA PROMOTER BINDING PROTEIN-LIKE genes in the control of heteroblasty[J].Development,2009,136:955-964
[2]Poethig R S.The past,present,and future of vegetative phase change[J].Plant Physiology,2010,154:541-544.
[3]Telfer A,Bollman K M,Poethig R S.Phase change and the regulation of trichome distribution in Arabidopsis thaliana[J].Development,1997,124:645-654.
[4]Wu G,Park M Y,Conway S R,et al.The sequential action of miR156 and miR172 regulates developmental timing in Arabidopsis[J].Cell,2009,138:750-759.
[5]Jacqmard A,Gadisseur I,Bernier G.Cell division and morphological changes in the shoot apex of Arabidopsis thaliana during floral transition[J].Annals of Botany,2003,91:571-576.
[6]Yang L,Conway S R,Poethig R S.Vegetative phase change is mediated by a leaf-derived signal that represses the transcription of miR156[J].Development,2011,138(2):245-249.
[7]Spanudakis E,Jackson S.The role of micro RNAs in the control of flowering time[J].Journal of Experimental Botany,2014,65(2):365-380.
[8]Wu G,Park M Y,Conway S R,et al.The sequential action of miR156 and miR172 regulates developmental timing in Arabidopsis[J].Cell,2009,138:750-759.
[9]Gou J Y,Felippes Felipe F,Liu C J,et al.Negative regulation of anthocyanin biosynthesis in Arabidopsis by a miR156-Targeted SPL transcription factor[J].Plant Cell,2011,23(4):1512-1522.
[10]Tsuyoshi M,Kay W,Yoshie H,et al.LHY and CCA1 are partially redundant genes required to maintain circadian rhythms in Arabidopsis[J].Developmental Cell,2002,2(5):629-641.
[11]Schaffer R,Landgraf J,Accerbi M,et al.Microarray analysis of diurnal and circadian-regulated genes in Arabidopsis[J].The Plant Cell,2001,13(1):113-123.
[12]Gendron Joshua M,Pruneda-Paz JoséL,Doherty Colleen J,et al.Arabidopsis circadian clock protein,TOC1,is a DNA-binding transcription factor[J].Proceedings of the National Academy of Sciences of the United States of America,2012,109(8):3167-3172.
[13]Alabadílaba Oyama T,Yanovsky M J,et al.Reciprocal regulation between TOC1 and LHY/CCA1 within the Arabidopsis circadian clock[J].Science,2001,293(5531):880-883.
[14]郭蕊.拟南芥生物节律钟相关基因LHY、CCA1和GI对其营养生长时相转变的作用[D].天津:天津农学院,2017.
[15]李和平.植物显微技术[M].2版.北京:科学出版社,2009:12-14,29,32-33.
[16]卢阳,龙鸿.拟南芥叶片数目变化突变体对营养生长时相转变的影响[J].植物学报,2015,50(3):331-337.
[17]Usami T,Horiguchi G,Yano S,et al.The more and smaller cells mutants of Arabidopsis thaliana identify novel roles for SQUAMOSA PROMOTER BINDING PROTEIN-LIKE genes in the control of heteroblasty[J].Development,2009,136:955-964