植物硼营养研究的重要进展与展望

硼是高等植物必需的矿质营养元素, 但是人们对硼行使生理功能及其分子机理的认识远落后于其它必需营养元素。近几年国际上植物硼营养的研究取得了一些重要的突破。首先是进一步明确了B-RG-II复合物的形成及其影响细胞壁结构和功能的分子机制, 并且发现B-RG-II的形成及其含量与陆生植物的进化密切相关。其次是在拟南芥中克隆了第一个植物硼转运子基因 BOR1, 并揭示了它的作用机理; 通过转基因实验证明了植物硼的高效吸收与水通道基因NIP5;1密切相关。进而通过大量的种质筛选, 从油菜、小麦、大麦及棉花等农作物中获得一批硼高效吸收利用的优异种质材料, 并开展了硼高效QTL定位和克隆。本文详细综述了以上几个方面的研究进展, 并对进一步的研究做了展望。

Main Progresses in Boron Nutrition Research in Plants

Boron (B) is an essential mineral nutrient for higher plants. However, its physiological role in plants and its molecular mechanism are still not well understood. This paper summarizes substantial progress achieved in recent years and unresolved questions. The molecular mechanisms of B cross-linking with rhamnogalacturonan II (RG-II) to form B-RG-II complex and its important role in the development and stability of the cell wall was verified. Moreover, the enhanced formation of B-RG-II seems to be closely related to the conquering of land during plant evolution. As well, genetic engineering has confirmed that the first B transporter, BOR1, involved in xylem loading and cloned in Arabidopsis, and NIP5;1, a member of the major intrinsic protein family, function as a boric acid channel for B uptake and are crucial for plant growth and development under B limitation in Arabidopsis. Finally, some valuable germplasms for high B-utilization efficiency were screened in rapeseed, wheat, and barley, and the mapping and cloning of quantitative trait loci for tolerance to B deficiency or B toxicity are in good progress.