摘要
MYB转录因子(v-myb avian myeloblastosis viral oncogene homolog)家族在植物应答低磷胁迫中发挥重要作用,在前期工作中,我们通过马尾松(Pinus massoniana)耐低磷种质转录组分析,发掘了应答低磷胁迫的MYB类转录因子。为了进一步验证马尾松MYB基因Pm MYB169在磷吸收及利用上的功能,本研究在已克隆Pm MYB169基因的基础上,构建Pm MYB169正义表达载体,采用浸花转化法转化拟南芥。经抗性筛选及检测,得到2株T3代纯合株系,选择表达量较高株系进行低磷(0.1 mmol/L)处理。结果表明,在正常条件下,转基因与野生型拟南芥的酸性磷酸酶活性(acid phosphatase, APase)、生物量,无机磷及总磷含量均无明显差异;而在低磷条件下,转基因植株中Pm MYB169基因表达上调,其中在根部表达较为明显,转基因植株根部磷转运蛋白PHT1;1的表达量也高于野生型,酸性磷酸酶活性是野生型的2.21倍;与野生型相比,转基因根部无机磷和总磷分别提高了1.40倍、1.53倍,地上部含量分别提高1.21倍、1.40倍;除此之外,转基因植株根部干重、地上部干重及总干重均显著高于野生型。因此,超表达Pm MYB169基因改善了转基因拟南芥有效磷的利用率,提高了耐低磷能力,这为进一步理解MYB基因在马尾松应答低磷胁迫的机制,以及耐低磷种质的早期筛选提供了理论参考。
MYB transcription factor(v-myb avian myeloblastosis viral oncogene homolog) family plays an important role in response of plants to low phosphorus stress. In the previous work, MYB transcription factors, responding to low phosphorus stress, were discovered through transcriptome analysis of Pinus massoniana germplasm with low phosphorus tolerance. To further verify the function of Pinus massoniana MYB gene Pm MYB169 in phosphorus absorption and utilization, the just expression vector of Pm MYB169 was constructed and Arabidopsis thaliana was transformed with floral dipping transformation method based on the cloned Pm MYB169 gene. After resistance screening and detection, two T3 homozygous lines were obtained, and the lines with higher expression level were selected for low phosphorus(0.1 mmol/L) treatment. The results showed that, under the normal conditions, there were no significant differences in acid phosphatase(APase) activity, biomass, inorganic phosphorus and total phosphorus between transgenic and the wild type Arabidopsis thaliana. While under low phosphorus conditions, the expression of PmMYB169 gene was up-regulated in the transgenic lines, among which the expression level in root was more obvious. The expression of phosphate transporter protein PHT1;1 in the root of the transgenic lines was also higher than that of the wild type. The acid phosphatase activity of the transgenic line was2.21 times as high as that of the wild type. Compared with the wild type, the contents of inorganic phosphorus and total phosphorus in the transgenic root increased by 1.40 and 1.53 times, respectively, and that of the above ground part of plants increased by 1.21 and 1.40 times, respectively. Furthermore, root dry weight, above ground dry weight and total dry weight of transgenic plants also increased significantly in comparison with that of the wild type. Therefore, overexpression of PmMYB169 substantially improved the utilization of available phosphorus and enhanced the ability of low phosphorus tolerance in transgenic
作者
李慧平
王庆竹
汤纬玮
文晓鹏
Li Huiping;Wang Qingzhu;Tang Weiwei;Wen Xiaopeng(Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education),Institute of Agro-Bioengineering,College of Life Sciences,Guizhou University,Guiyang,550025;College of Forestry,Guizhou University,Guiyang,550025)
出处
《分子植物育种》
CAS
CSCD
北大核心
2018年第24期8048-8055,共8页
Molecular Plant Breeding
基金
国家重点研发项目(2017YFD0600303-4)
国家自然科学基金(201660185)共同资助.
