Page 90 - 《广西植物》2024年第7期
P. 90
1 2 9 0 广 西 植 物 44 卷
( 1. College of Life Science and Agro ̄Forestry of Qiqihar Universityꎬ Qiqihar 161006ꎬ Heilongjiangꎬ Chinaꎻ 2. Branch of Animal Husbandry
and Veterinary of Heilongjiang Academy of Agricultural Sciencesꎬ Qiqihar 161005ꎬ Heilongjiangꎬ Chinaꎻ 3. Keshan
Branch of Heilongjiang Academy of Agricultural Sciencesꎬ Qiqihar 161606ꎬ Heilongjiangꎬ China )
Abstract: Expansin (EXP) plays an important role in plant response to environmental stress by regulating cell wall
relaxation. To explore the role of EXP genes in soybean response to abiotic stressꎬ two soybean EXP genes (GmEXPB5 and
GmEXPB7) and their protein sequences were analyzed by bioinformaticsꎬ and their expression levels were detected by real ̄
time fluorescent quantitative PCR (qRT ̄PCR). The results were as follows: (1) The GmEXPB5 and GmEXPB7 were
located on chromosomes 10 and 12 of soybeanꎬ and encoded proteins containing 272 and 267 amino acidsꎬ respectively. The
molecular weight of GmEXPB5 protein was 29.07 kD and the theoretical isoelectric point was 7.51. The molecular weight of
GmEXPB7 protein was 29.09 kD and the theoretical isoelectric point was 8.66. Both GmEXPB5 and GmEXPB7 were stable
hydrophilic proteinsꎬ and localized in the cell wall. Both GmEXPB5 and GmEXPB7 proteins contained a signal peptide
sequence and a conserved DPBB_1 structural domain. (2) GmEXPB5 protein had the closest affinity with CaEXPB15
protein of Cicer arietinumꎬ and GmEXPB7 protein was closely related to EXPB3 proteins of Spatholobus suberectusꎬ Vigna
angularis and V. unguiculata. (3) GmEXPB5 and GmEXPB7 were expressed in rootꎬ stem and leaf of soybeanꎬ and their
expression levels in root and leaf were significantly higher than those in stem. (4) GmEXPB5 and GmEXPB7 could respond
to saltꎬ drought and cold stresses in soybean seedlings. (5) The promoter region of GmEXPB5 contained two types of stress ̄
related cis ̄elements (ABRE and ARE). The promoter region of GmEXPB7 contained five types of stress ̄related cis ̄elements
(ABREꎬ AREꎬ CGTCA ̄motifꎬ TC ̄rich repeats and MBS). In conclusionꎬ these results indicate that GmEXPB5 and
GmEXPB7 can participate in the response of soybean to abiotic stress.
Key words: soybean (Glycine max)ꎬ expansinꎬ bioinformatics analysisꎬ abiotic stressꎬ expression analysis
膨胀素( expansinꎬEXP) 是一种参与改变植物 2019)、营养吸收( Zhou et al.ꎬ 2014) 和种子产量
细胞壁发育过程的非水解活性松弛蛋白ꎬ又称扩 (Calderini et al.ꎬ 2021) 等植物生长发育过程中发
展蛋白ꎮ EXP 于 1992 年在酸诱导黄瓜下胚轴细 挥重要作用ꎮ 此外ꎬEXP 基因参与调控植物非生
胞壁伸长的研究中首次被发现( McQueen ̄Mason et 物胁迫的研究也在逐渐开展ꎮ 例如:干旱和缺磷
al.ꎬ 1992)ꎮ 后续从植物细胞壁中纯化并鉴定出 条件能够诱导水稻 OsEXPB2 基因的表达( 文文乙
多种 EXPꎬ如拟南芥、番茄、烟草和水稻等( 张安 豪ꎬ2013 )ꎻ 遭 遇 盐 胁 迫 时ꎬ 玉 米 抗 盐 品 种 中
等ꎬ2013)ꎮ EXP 广 泛 存 在 与 植 物 中ꎬ 主 要 包 括 ZmExpB2、ZmExpB6 和 ZmExpB8 的 表 达 量 上 调
EXPA ( α ̄expansin )、 EXPB ( β ̄expansin )、 EXLA (Geilfus et al.ꎬ 2010)ꎻ谷子 SiEXPB5 在干旱胁迫
(expansin ̄like A)和 EXLB( expansin ̄like B)4 个亚 下表达量增加ꎬ其异源表达能够增强转基因拟南
家族( Sampedro & Cosgroveꎬ 2005)ꎮ 其中ꎬEXPA 芥的抗旱性( 王金荣ꎬ2020)ꎻ野生大豆 GsEXPB1
和 EXPB 两个亚家族蛋白数量在植物中占多数ꎬ 对促进大豆根系生长及耐盐性的提高起到积极作
EXPA 主要存在于双子叶植物和非禾本科单子叶 用(Feng et al.ꎬ 2022)ꎻ野生大麦 HvEXPB7 通过促
植物中ꎬ而 EXPB 则多存在于禾本科单子叶植物 进根毛伸长来增强抗旱性( He et al.ꎬ 2015)ꎻ过表
中ꎮ 对于 EXLA 和 EXLB 数量的相关研究较少ꎬ最 达小麦 TaEXPB23 使转基因烟草抗旱性得到提高
初是在水稻和拟南芥中被发现(徐筱等ꎬ2010)ꎮ (Li et al.ꎬ 2011)ꎬ而 TaEXPB7 ̄B 则参与转基因拟
研究表明ꎬEXP 基因在调节细胞大小( Yin et 南芥对低温胁迫的耐受性( Feng et al.ꎬ 2019)ꎻ拟
al.ꎬ 2023)、种子萌发( Yan et al.ꎬ 2014)、根伸长 南芥 AtEXP3 和 AtEXP ̄β1 的过表达则提高了转基
( Noh et al.ꎬ 2013)、叶生长(Zhou et al.ꎬ 2015)、茎 因植株对盐胁迫的敏感性(Kwon et al.ꎬ 2008)ꎮ
节间伸长(Kuluev et al.ꎬ 2014)、气孔开合( Wei et 大豆是植物油和蛋白质的主要来源之一ꎬ其特
al.ꎬ 2011)、花发育( Kuluev et al.ꎬ 2012)、果实软 殊的固氮能力使其成为轮作系统和间作栽培模式
化 成 熟 ( Brummell et al.ꎬ 1999ꎻ Jiang et al.ꎬ 中的高利润作物(Liu et al.ꎬ 2020)ꎮ 大豆在生长过