Page 68 - 《广西植物》2020年第7期
P. 68

9 6 4                                 广  西  植  物                                         40 卷
      ( 1. School of Life Sciencesꎬ Northeast Forestry Universityꎬ Harbin 150040ꎬ Chinaꎻ 2. State Key Laboratory of Tree Genetics and Breedingꎬ
      Northeast Forestry Universityꎬ Harbin 150040ꎬ Chinaꎻ 3. Forestry Bureau of Shanhetun Countyꎬ Wuchang 150232ꎬ Heilongjiangꎬ Chinaꎻ
                       4. Forestry Bureau of Dahailin Countyꎬ Mudanjiang 157000ꎬ Heilongjiangꎬ China )

       Abstract: PHAVOLUTA(PHV)transcription factor is one of the most important members of homeodomain ̄leucine zipper
       Ⅲ (HD ̄ZIP ) familyꎬ and plays an important role in the regulation of formation of plant stems apical and germ
       meristem. In this researchꎬ the PHV gene of Fraxinus mandshurica was acquired by gene cloning and was named by
       FmPHV. Detailed bioinformatics analysis showed that the length of FmPHV gene was 2 112 bpꎬ and contained a com ̄
       plete Open Reading Frame (ORF) which encoded a protein with 703 amino acids. The FmPHV gene encoded a stable
       hydrophilic proteinꎬ the subcellular localization prediction of FmPHV protein showed the FmPHV was mainly present in
       the chloroplast. Conserved domain and homology analysis of FmPHV protein indicated thatꎬ the homology of FmPHV be ̄
       tween the homology PHV proteins in other speciesꎬ such as Olea europaeanꎬ Sesamum indicum and Nicotiana tabacumꎬ
                                                        ̄1
       was 99%. Under 4 ℃ conditionꎬ with the treatment of 50 mgL 3 ̄indolebutyric acid(IBA)solutionꎬ we obtained the
       cambium callus from cambium stem cells of Fraxinus mandshurica. Analysis of the gene expression pattern of FmPHV
       showed that the FmPHV was the highest expression in June. Furthermoreꎬ the expression of FmPHV in buds was stronger
       than which in any other tissues. Compared with the callus from different sourcesꎬ which obtained from the bark of
       F. mandshuricaꎬ the expression level of FmPHV gene in callusꎬ derived from meristem formationꎬ was significantly high ̄
       er than which from other sources. Moreoverꎬ overexpression the FmPHV gene in F. mandshurica seedlings will reduce the
       expression of auxin ̄related genes and increase the expression of cytokinin ̄related genes. This phenomenon indicated that
       the function of FmPHV gene was more beneficial to the process of plant shoot differentiation and regeneration. In summa ̄
       ryꎬ this research revealed the expression pattern of FmPHV gene during the growth and development in F.
       mandshurica. And revealed the expression pattern of key genes in plant shoot regeneration pathwayꎬ which were regulated
       by FmPHV gene. Our research reveals the potential value of the molecular characteristic of FmPHV gene in the response
       of auxin and cytokinin pathways during the process of the formation of plant callus generation.
       Key words: Fraxinus mandshuricaꎬ PHV geneꎬ bioinformatic analysisꎬ transient infectionꎬ cambium cell


       HOMEO ̄DOMAIN LEUCINE ZIPPER CLASS             在不同的通路中发挥着重要的功能ꎬ包括 REVOLUTA
   (HD ̄ZIP)转录因子家族是植物中所特有的一类转                         ( REV/ IFL ̄1/ AVB ̄1)、 PHABULOSA ( PHB/ AtHB ̄9)、
   录因子(Sessa et al.ꎬ2018)ꎮ 根据氨基酸序列同源                 PHAVOLUTA ( PHV/ AtHB ̄14)、 CORONA ( CNA/ AtHB ̄
   性的不同ꎬ植物 HD ̄ZIP 转录因子可分为 I ̄IV 共四                    15)和 AtHB ̄8(Zhong & Yeꎬ 2001)ꎮ HD ̄ZIP Ⅲ蛋白
   类ꎬ其 共 同 特 点 是 都 含 有 DNA 结 合 同 源 域                 是茎端分生组织命运的主要 调 节 因 子 ( Smith et
   homeodomain (HD)和 basic leucine zipper(bZIP)结     al.ꎬ2010)ꎮ Zhang et al.(2017)的研究表明ꎬrev phb
   构域( Thakur et al.ꎬ2006)ꎮ 其中 HD ̄ZIP Ⅱ家族            phv 三重突变体表现出无子叶的表型ꎬ其茎尖分生
   的主要功能是调控维管系统原发性和继发性组织                             组织呈现出针状结构ꎬ并且能够观察到茎尖分生
   形成以及茎尖分生组织三层结构的建成与维持                              组织的分离现象ꎬ说明 HD ̄ZIP Ⅲ转录因子在胚芽

   (Caroline et al.ꎬ2010ꎻZhang et al.ꎬ2017)ꎮ HD ̄ZIP Ⅲ  形成过程的不可替代的作用ꎮ
   类蛋白有一个保守的 steroidogenic acute regulatory              HD ̄ZIP Ⅲ转录因子家族通过直接调控抑制
   protein ̄related domain associated with the lipid ̄transfer  HISTIDINE  PHOSPHOTRANSFER  PROTEIN  6
   (START)结构域ꎬ其 C 末端序列高度保守ꎬ 包含一                      (AHP6)表达ꎬ同时也促进细胞分裂素( cytokininꎬ
   个由甲硫氨酸-谷氨酸-赖氨酸-组氨酸-亮氨酸-                           CK)信号传导ꎬ通过 CK 信号在茎尖分生组织空间
   丙氨 酸 ( MEKHLA) 构 成 的 结 构 域 ( Qin et al.ꎬ          结构中与 AHP6 的负反馈调节系统间接调控 AHP6
   2009)ꎮ 拟南芥中ꎬ共有五种 HD ̄ZIP Ⅲ蛋白质ꎬ并                    的表达( Bishopp et al.ꎬ2011)ꎮ HD ̄ZIP 转录因子
   63   64   65   66   67   68   69   70   71   72   73