Improved phosphorus acquisition by tobacco through transgenic expression of mitochondrial malate dehydrogenase from Penicillium oxalicum
Improved phosphorus acquisition by tobacco through transgenic expression of mitochondrial malate dehydrogenase from Penicillium oxalicum
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DOI：
10.1007/s00299-011-1138-3
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发表时间：
2012-01-01
影响因子：
6.2
通讯作者：
An, Lijia
中科院分区：
文献类型：
--
作者：
Lu, Jun;Gao, Xiaorong;An, Lijia
磷（P）是植物生长和发育的必需营养素，但在土壤中通常无法利用和获取，因为施用的磷在酸性土壤中主要固定在铝（Al）和铁（Fe）上，在碱性土壤中主要固定在钙（Ca）上。增加有机酸排泄被认为是植物利用磷来增强磷吸收的机制之一。在这项研究中，我们过量表达的线粒体苹果酸脱氢酶（MDH）基因的菌根真菌Penicilliumsativicum烟草。与野生型相比，转基因株系的MDH活性显著提高。缺磷诱导的转基因株系根系分泌物中苹果酸含量是相同条件下野生型的1.3 ~ 2.9倍。在选择用于分析的转基因品系中，一个品系（M1）显示出最高水平的MDH活性和苹果酸渗出物。与野生型相比，M1在磷酸铝、磷酸铁和磷酸钙培养基中生长时，生物量分别增加了149.0%、128.5%和127.9%。M1也有更好的磷吸收相比，野生型，与总磷含量增加了287.3%，243.5%，和223.4%，当生长在铝磷酸盐，铁磷酸盐，钙磷酸盐介质。据我们所知，这是第一个研究提高植物利用磷的能力，从铝磷酸盐，铁磷酸盐，钙磷酸盐通过操纵植物的有机酸代谢，通过基因工程。
Phosphorus (P) is an essential nutrient for plant growth and development, but is generally unavailable and inaccessible in soil, since applied P is mostly fixed to aluminium (Al) and ferrum (Fe) in acidic soils and to calcium (Ca) in alkaline soils. Increased organic acid excretion is thought to be one mechanism by which plants use to enhance P uptake. In this study, we overexpressed a mitochondrial malate dehydrogenase (MDH) gene from the mycorrhizal fungi Penicillium oxalicum in tobacco. The MDH activity of transgenic lines was significantly increased compared to that of wild type. Malate content in root exudation of transgenic lines induced in response to P deficiency was 1.3- to 2.9-fold greater than that of wild type under the same condition. Among the transgenic lines that were selected for analysis, one line (M1) showed the highest level of MDH activity and malate exudate. M1 showed a significant increase in growth over wild type, with 149.0, 128.5, and 127.9% increases in biomass, when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. M1 also had better P uptake compared to wild type, with total P content increased by 287.3, 243.5, and 223.4% when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. To our knowledge, this is the first study on improving the ability of a plant to utilize P from Al-phosphate, Fe-phosphate, and Ca-phosphate by manipulating the organic acid metabolism of the plant through genetic engineering.