Making of multi-tolerant plants against complexed acid-soil stresses by molecular modifications of membrane lipid layers

为了降低根中磷脂的含量，增加根中甾醇的含量，我们采用了两种不同的技术，即培养法和分子法对新植株进行了改良：以前在缺磷条件下生长的铝敏感水稻品种Koshihikari，通过过表达PAH(磷脂转化为半乳糖脂的关键基因)和HMG(生物合成甾醇的关键基因)来获得转基因植株。缺磷铝敏感的Koshihikari的耐铝性和低pH条件下的低钙耐性显著提高，转化的Koshihikari的几个品系的耐铝性和低P耐性也得到提高。在几十个水稻品种中，耐低磷水稻品种对含磷代谢产物的分解具有独特的特点。几个与磷循环能力有关的基因与每种功能一起被识别出来。

In order to lower the content of phospholipids and to increase that of sterols in roots, we made the new plants by modification using two different techniques, i.e., culturing method and molecular method: Al-sensitive rice cultivar Koshihikari grown previously under P-deficient conditions and transformed by the overexpressions of PAH (key gene to exchange phospholipids into galactolipids) and HMG (key gene to biosynthesize sterols). Al tolerance and low-Ca tolerance under low pH conditions of P-deficient Al-sensitive Koshihikari were significantly enhanced, and Al tolerance and low-P tolerance of the several lines of the transformed Koshihikari were also enhanced. Among several tens of rice cultivars, low-P tolerant rice cultivar was found out to have a specific characteristics on the decomposition of P-containing metabolites. Several genes contributing to P-recycling ability were identified together with each function.