n nnnThe development and activity of the procambium and cambium,which ensure vascular tissue formation, is critical for overallplant architecture and growth. However, little is known aboutthe molecular factors affecting the activity of vascular meristemsand vascular tissue formation. Here, we show that the His kinaseCYTOKININ-INDEPENDENT1 (CKI1) and the cytokinin receptors ARABIOPSISHISTIDINE KINASE2 (AHK2) and AHK3 are important regulators ofvascular tissue development in Arabidopsis thaliana shoots.Genetic modifications of CKI1 activity in Arabidopsis causedysfunction of the two-component signaling pathway and defectsin procambial cell maintenance. CKI1 overexpression in protoplastsleads to cytokinin-independent activation of the two-componentphosphorelay, and intracellular domains are responsible forthe cytokinin-independent activity of CKI1. CKI1 expressionis observed in vascular tissues of inflorescence stems, andCKI1 forms homodimers both in vitro and in planta. Loss-of-functionahk2 and ahk3 mutants and plants with reduced levels of endogenouscytokinins show defects in procambium proliferation and an absenceof secondary growth. CKI1 overexpression partially rescues ahk2ahk3 phenotypes in vascular tissue, while the negative mutationCKI1H405Q further accentuates mutant phenotypes. These resultsindicate that the cytokinin-independent activity of CKI1 andcytokinin-induced AHK2 and AHK3 are important for vascular bundleformation in Arabidopsis.展开▼
机译:ABSTRACTn FONT> TH> TR> TABLE> n
n TOP n <字体颜色= 464c53>抽象 FONT> n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n FONT> TH> TR> TABLE> n nnn菌丝和形成层的发育和活性, SUP>确保维管组织的形成对于整个 SUP>植物的结构和生长至关重要。但是,关于 SUP>影响血管分生组织 SUP>和血管组织形成的分子因素知之甚少。在这里,我们表明,His激酶 SUP>细胞分裂素独立1(CKI1)和细胞分裂素受体ARABIOPSIS SUP>组氨酸激酶2(AHK2)和AHK3是 SUP的重要调控因子拟南芥 I>芽中的血管组织发育。 SUP> 拟南芥 I>中CKI1活性的基因修饰导致 SUP>功能障碍成分信号通路和肌间质细胞维持中的缺陷 SUP>。 CKI1 I>在原生质体中的过表达 SUP>导致细胞分裂素非依赖性激活两种成分的 SUP>磷胶质,而胞内结构域负责 SUP > CKI1的细胞分裂素非依赖性活性。在花序茎的维管组织中观察到 CKI1 I>表达 SUP>,并且 SUP> CKI1在体内和体外均形成同型二聚体。功能丧失 SUP> ahk2 I>和 ahk3 I>突变体以及内源性 SUP>细胞分裂素水平降低的植物显示出原菌增殖缺陷并且没有 SUP>二次增长。 CKI1过表达可部分挽救血管组织中的 ahk2 SUP> ahk3 I>表型,而负突变 SUP> CKI1 H405Q SUP>则进一步加重了突变型。这些结果 SUP>表明,CKI1和 SUP>细胞分裂素诱导的AHK2和AHK3的细胞分裂素非依赖性活性对于拟南芥中的血管束 SUP>形成很重要。 I>。 SUP>
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Department of Functional Genomics and Proteomics, Institute of Experimental Biology, Faculty of Science, Masaryk University, CZ-61137, Brno, Czech Republic;
Department of Life Sciences and Functional Genomics Center, Pohang University of Science and Technology, Pohang 790-784, Korea;
Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Korea|Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea;
Department of Functional Genomics and Proteomics, Institute of Experimental Biology, Faculty of Science, Masaryk University, CZ-61137, Brno, Czech Republic;
Department of Life Sciences and Functional Genomics Center, Pohang University of Science and Technology, Pohang 790-784, Korea;
Department of Life Sciences and Functional Genomics Center, Pohang University of Science and Technology, Pohang 790-784, Korea;
Institute of Biophysics AS CR, CZ-612 65, Brno, Czech Republic|Mendel University of Agriculture and Forestry in Brno, CZ-613 00, Brno, Czech Republic;
Department of Functional Genomics and Proteomics, Institute of Experimental Biology, Faculty of Science, Masaryk University, CZ-61137, Brno, Czech Republic;
Department of Functional Genomics and Proteomics, Institute of Experimental Biology, Faculty of Science, Masaryk University, CZ-61137, Brno, Czech Republic;
Institut für Biologie II/Botany, Freiburg Institute of Advances Studies, Centre of Biological Signaling Studies, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany;
Institute of Biophysics AS CR, CZ-612 65, Brno, Czech Republic|Mendel University of Agriculture and Forestry in Brno, CZ-613 00, Brno, Czech Republic;
Department of Life Sciences and Functional Genomics Center, Pohang University of Science and Technology, Pohang 790-784, Korea;