Secondary vascular tissue(SVT)development and regeneration are regulated by phytohormones.In this study,we used an in vitro SVT regeneration system to demonstrate that gibberellin(GA)treatment significantly promotes a...Secondary vascular tissue(SVT)development and regeneration are regulated by phytohormones.In this study,we used an in vitro SVT regeneration system to demonstrate that gibberellin(GA)treatment significantly promotes auxin-induced cambium reestablishment.Altering GA content by overexpressing or knocking down ent-kaurene synthase(KS)affected secondary growth and SVT regeneration in poplar.The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE(PtoGAI)is expressed in a specific pattern during secondary growth and cambium regeneration after girdling.Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration,and the inhibition of cambium regeneration could be partially restored by GA application.Further analysis of the PtaDR5:GUS transgenic plants,the localization of PIN-FORMED 1(PIN1)and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of PIN1,which mediates auxin transport during SVT regeneration.Taken together,these findings suggest that GA promotes cambium regeneration by stimulating auxin signal transduction.展开更多
Vascular cambium produces the phloem and xylem,vascular tissues that transport resources and provide mechanical support,making it an ideal target for crop improvement.However,much remains unknown about how vascular ca...Vascular cambium produces the phloem and xylem,vascular tissues that transport resources and provide mechanical support,making it an ideal target for crop improvement.However,much remains unknown about how vascular cambium proliferates.In this study,through pharmaceutical and genetic manipulation of reactive oxygen species(ROS)maxima,we demonstrate a direct link between levels of ROS and activity of LATERAL ORGAN BOUNDARIES DOMAIN 11(LBD11)in maintaining vascular cambium activity.LBD11 activates the transcriptionof several keyROS metabolic genes,including PEROXIDASE71and RESPIRATORY BURST OXIDASE HOMOLOGS D and F,to generate local ROS maxima in cambium,which in turn enhance the proliferation of cambial cells.In a negative feedback mechanism,higher Ros levels then repress LBD11 expression and maintain the balance of cambial cell proliferation.Our findings thus reveal the role of a novel LBD11/ROS-dependent feedback regulatory system in maintaining vascular cambiumspecific redox homeostasis and radial growth inplants.展开更多
During plant growth and development mineral elements are preferentially delivered to different organs and tissues to meet the differential demand. It has been shown that the preferential distribution of mineral nutrie...During plant growth and development mineral elements are preferentially delivered to different organs and tissues to meet the differential demand. It has been shown that the preferential distribution of mineral nutrients in gramineous plants is mediated by node-based transporters, but the mechanisms of preferential distribution in dicots are poorly understood. Here, we report a distinct mechanism for the preferential distribution of phosphorus (P) in Arabidopsis plants, revealed by detailed functional analysis of AtSPDT/AtSULTR3;4 (SULTR-like P Distribution Transporter), a homolog of rice OsSPDT. Like OsSPDT, AtSPDT is localized at the plasma membrane and showed proton-dependent transport activity for P. Interestingly, we found that AtSPDT is mainly expressed in the rosette basal region and leaf petiole, and its expression is up-regulated by P deficiency. Tissue-specific analysis showed that AtSPDT is mainly located in the vascular cambium of different organs, as well as in the parenchyma tissues of both xylem and phloem regions. Knockout of AtSPDT inhibited the growth of new leaves under low P due to decreased P distribution to those organs. The seed yields of the wild-type and atspdt mutant plants are similar, but the seeds of mutant plants contain – less P. These results indicate that AtSPDT localized in the vascular cambium is involved in preferential distribution of P to the developing tissues, through xylem-to-phloem transfer mainly at the rosette basal region and leaf petiole.展开更多
While monocots lack the ability to produce a vascular cambium or woody growth, some monocot lineages evolved a novel lateral meristem, the monocot cambium, which supports secondary radial growth of stems. In contrast ...While monocots lack the ability to produce a vascular cambium or woody growth, some monocot lineages evolved a novel lateral meristem, the monocot cambium, which supports secondary radial growth of stems. In contrast to the vascular cambium found in woody angiosperm and gymnosperm species, the monocot cambium produces secondary vascular bundles, which have an amphivasal organization of tracheids encircling a central strand of phloem. Currently there is no information concerning the molecular genetic basis of the development or evolution of the monocot cambium. Here we report high-quality transcriptomes for monocot cambium and early derivative tissues in two monocot genera, Yucca and Cordyline. Monocot cambium transcript profiles were compared to those of vascular cambia and secondary xylem tissues of two forest tree species, Populus trichocarpa and Eucalyptus grandis. Monocot cambium transcript levels showed that there are extensive overlaps between the regulation of monocot cambia and vascular cambia. Candidate regulatory genes that vary between the monocot and vascular cambia were also identified, and included members of the KANADI and CLE families involved in polarity and cell-cell signaling, respectively. We suggest that the monocot cambium may have evolved in part through reactivation of genetic mechanisms involved in vascular cambium regulation.展开更多
In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating...In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.展开更多
In this Special Issue,a focus is placed on the role of the itdxylem as an essential conduit for the long-distance Edelivery of water and mineral nutrients from the soil to the vegetative(above-ground)regions of the pl...In this Special Issue,a focus is placed on the role of the itdxylem as an essential conduit for the long-distance Edelivery of water and mineral nutrients from the soil to the vegetative(above-ground)regions of the plant Xylem cells destined to form tracheids or vesse members,which will make up the conduit for this water and mineral transport from the roots to the shoots,undergo apoptosis,a process of展开更多
基金supported by grants from the National Natural Science Foundation of China(32071726,32271825)to Xin-qiang He.
文摘Secondary vascular tissue(SVT)development and regeneration are regulated by phytohormones.In this study,we used an in vitro SVT regeneration system to demonstrate that gibberellin(GA)treatment significantly promotes auxin-induced cambium reestablishment.Altering GA content by overexpressing or knocking down ent-kaurene synthase(KS)affected secondary growth and SVT regeneration in poplar.The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE(PtoGAI)is expressed in a specific pattern during secondary growth and cambium regeneration after girdling.Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration,and the inhibition of cambium regeneration could be partially restored by GA application.Further analysis of the PtaDR5:GUS transgenic plants,the localization of PIN-FORMED 1(PIN1)and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of PIN1,which mediates auxin transport during SVT regeneration.Taken together,these findings suggest that GA promotes cambium regeneration by stimulating auxin signal transduction.
基金grants to I.H.from the New Breeding Technologies Development Program funded by the Rural Development Administration,Republic of Korea(project no.PJ016538)from the National Research Foundation of Korea(NRF)grant funded by the Ministry of Science and ICT,Republic of Korea(project no.2020R1A2C3012750)+1 种基金Brain Pool Program through the NRF funded by the Ministry of Science and ICT(grant no.2017H1D3A1A03055171)Basic Science Research Program through the NRF funded by the Ministry of Education(grant no.2019R1/1A1A01055449).
文摘Vascular cambium produces the phloem and xylem,vascular tissues that transport resources and provide mechanical support,making it an ideal target for crop improvement.However,much remains unknown about how vascular cambium proliferates.In this study,through pharmaceutical and genetic manipulation of reactive oxygen species(ROS)maxima,we demonstrate a direct link between levels of ROS and activity of LATERAL ORGAN BOUNDARIES DOMAIN 11(LBD11)in maintaining vascular cambium activity.LBD11 activates the transcriptionof several keyROS metabolic genes,including PEROXIDASE71and RESPIRATORY BURST OXIDASE HOMOLOGS D and F,to generate local ROS maxima in cambium,which in turn enhance the proliferation of cambial cells.In a negative feedback mechanism,higher Ros levels then repress LBD11 expression and maintain the balance of cambial cell proliferation.Our findings thus reveal the role of a novel LBD11/ROS-dependent feedback regulatory system in maintaining vascular cambiumspecific redox homeostasis and radial growth inplants.
基金This work was supported by a Grant-in-Aid for Specially Promoted Research(JSPS KAKENHI grant number 16H06296 to J.F.M.).
文摘During plant growth and development mineral elements are preferentially delivered to different organs and tissues to meet the differential demand. It has been shown that the preferential distribution of mineral nutrients in gramineous plants is mediated by node-based transporters, but the mechanisms of preferential distribution in dicots are poorly understood. Here, we report a distinct mechanism for the preferential distribution of phosphorus (P) in Arabidopsis plants, revealed by detailed functional analysis of AtSPDT/AtSULTR3;4 (SULTR-like P Distribution Transporter), a homolog of rice OsSPDT. Like OsSPDT, AtSPDT is localized at the plasma membrane and showed proton-dependent transport activity for P. Interestingly, we found that AtSPDT is mainly expressed in the rosette basal region and leaf petiole, and its expression is up-regulated by P deficiency. Tissue-specific analysis showed that AtSPDT is mainly located in the vascular cambium of different organs, as well as in the parenchyma tissues of both xylem and phloem regions. Knockout of AtSPDT inhibited the growth of new leaves under low P due to decreased P distribution to those organs. The seed yields of the wild-type and atspdt mutant plants are similar, but the seeds of mutant plants contain – less P. These results indicate that AtSPDT localized in the vascular cambium is involved in preferential distribution of P to the developing tissues, through xylem-to-phloem transfer mainly at the rosette basal region and leaf petiole.
基金the US Forest ServiceUSDA AFRI grants 2011-67013-30062 and 2014-04041supported by NSF PGRP Fellowship grant IOS-1402064
文摘While monocots lack the ability to produce a vascular cambium or woody growth, some monocot lineages evolved a novel lateral meristem, the monocot cambium, which supports secondary radial growth of stems. In contrast to the vascular cambium found in woody angiosperm and gymnosperm species, the monocot cambium produces secondary vascular bundles, which have an amphivasal organization of tracheids encircling a central strand of phloem. Currently there is no information concerning the molecular genetic basis of the development or evolution of the monocot cambium. Here we report high-quality transcriptomes for monocot cambium and early derivative tissues in two monocot genera, Yucca and Cordyline. Monocot cambium transcript profiles were compared to those of vascular cambia and secondary xylem tissues of two forest tree species, Populus trichocarpa and Eucalyptus grandis. Monocot cambium transcript levels showed that there are extensive overlaps between the regulation of monocot cambia and vascular cambia. Candidate regulatory genes that vary between the monocot and vascular cambia were also identified, and included members of the KANADI and CLE families involved in polarity and cell-cell signaling, respectively. We suggest that the monocot cambium may have evolved in part through reactivation of genetic mechanisms involved in vascular cambium regulation.
基金supported by the Ministry of Science and Technology of the People’s Republic of China(2016YFD0600104)the National Natural Science Foundation of China(31630014)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27020104).
文摘In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.
文摘In this Special Issue,a focus is placed on the role of the itdxylem as an essential conduit for the long-distance Edelivery of water and mineral nutrients from the soil to the vegetative(above-ground)regions of the plant Xylem cells destined to form tracheids or vesse members,which will make up the conduit for this water and mineral transport from the roots to the shoots,undergo apoptosis,a process of
基金This research was supported by the National Key Basic Research Program of China,the National Natural Science Foundation of China (31130012) to L..L.,and the National Natural Science Foundation of China (30972329) to X.W
文摘在树的第二等的生长的一个关键问题是脉管的形成层房间的区别怎么被指导到 concurrentlyform 二不同纸巾:木部或韧皮部。类 III homeodomain 白氨酸拉链(HD 压缩 III ) 基因被知道在主要、第二等的 growth.However 的进程在脉管的系统的开始, patterning,和区别玩 criticalroles,这些基因怎么控制第二等的脉管的区别的机制是未知的。这里,我们显示出那 Populus 类 III HD 压缩基因, PtrHB7,优先地在 cambial 被表示地区。压制 PtrHB7 的植物在木部与减小在脉管的纸巾显示了重要变化但是韧皮部的增加。Transcriptionalanalysis 表明调整木部区别的基因是下面调整的,而基因调整韧皮部 differentiationwere 起来调整。相应地, PtrHB7 overexpression 向木部房间提高了 cambial 房间的区别,但是禁止了韧皮部区别。cambial 房间区别上的 PtrHB7 规定与它的抄本丰富被联系。一起,结果 demonstratedthat PtrHB7 在在剂量依赖者 manner.Key 在 processof Populus 第二等的生长控制在第二等的木部和韧皮部纸巾之间的平衡区别起一个关键作用词: