摘要
淀粉酶(BAM)介导的淀粉降解广泛参与植物生长发育和非生物胁迫响应等生物学过程。从前期苹果低温诱导转录组研究中分离到1个参与淀粉代谢的差异表达基因片段,克隆其cDNA全长并进行序列分析。结果表明该基因与拟南芥AtBAM3同源,命名为MdBAM3(GenBank登录号:KX276144.1)。该基因开放阅读框长度1641 bp,编码546个氨基酸。该蛋白含有完整的葡萄糖基水解酶结构域,保守的葡萄糖基水解酶结构域外环和内环结构,以及2个谷氨酸催化残基,该蛋白包含40个氨基酸残基的cTP(Chloroplast transport peptides),表明MdBAM3蛋白是定位于叶绿体的β-淀粉酶。利用实时荧光定量PCR技术分析模拟低温(4℃)和自然低温条件下MdBAM3的表达响应及组织表达模式,该基因受4℃模拟低温诱导快速表达;自然低温下该基因在叶芽、花芽、韧皮部中的表达均显著上调,在叶芽中表达量最高,具有组织特异性,且随植株休眠的进行呈先升后降的趋势,推测MdBAM3在苹果低温胁迫响应中具有重要功能。
Beta-amylase(BAM)-mediated starch degradation is widely involved in the regulation of plant biological processes,such as growth,development,and abiotic stress responses.A differentially expressed gene fragment involved in starch metabolism was isolated from the early study of apple low temperature-induced transcriptome study.Its cDNA was cloned and sequenced to show that the gene was homologous to Arabidopsis thaliana AtBAM3 and named MdBAM3(GenBank accession No.KX276144.1).The open reading frame of this gene was 1641 bp in length and the encoded protein contains 546 amino acid residues.The gene-encoded protein contained a complete glucosyl hydrolase domain,including flexible and inner loop structure,and two glutamate-ca talyzed residues.The cTP(Chloroplast transport peptides)comprising 40 amino acid residues indicated that the MdBAM3 was a chloroplast-localized beta-amylase.Real-time quantitative PCR was used to analyze the expression response and tissue expression pattern of the gene at artificial low temperature at 4℃and natural low temperature during dormant period.MdBAM3 was significantly and quickly induced by artificial low temperature at 4℃.Under the natural low temperature treatment,the expression of MdBAM3 in leaf bud,flower bud,and phloem was significantly up-regulated.The highest expression level was found in leaf buds,indicating the tissue-specificity of this gene.With the dormancy of the plants,the expression of MdBAM3 exhibited the changes of first rise and then fall in all detected tissues.It was speculated that MdBAM3 played an important role in the response of apple to low-temperature stress.
作者
王海波
王森
何平
常源升
李林光
何晓文
Wang Haibo;Wang Sen;He Ping;Chang Yuansheng;Li Linguang;He Xiaowen(Apple Genetic Breeding and Cultivation Engineering Laboratory of Shandong Province,Shandong Institte of Pomology,Taian,271000)
出处
《分子植物育种》
CAS
CSCD
北大核心
2020年第13期4205-4212,共8页
Molecular Plant Breeding
基金
山东省自然科学基金(ZR2017YL025)
山东省重点研发计划(2018GNC113018)
山东省泰安市科技发展计划(2017NS0095)共同资助。
