Research for the mechanisms of Mn uptake in lettuce and role of Mn in low pH induced root hair-formation

生菜吸锰机制及其在低pH诱导根毛形成中的作用研究

• 批准号: 16570037
• 负责人: INOUE Yasunori
• 金额: $ 1.98万
• 依托单位: Tokyo University of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16570037/
• 关键词: lettuce; root hair; manganese; low pH; 酵母; Ls-MDR1; Mn; Mnトランスポーター; SMF1,2

Growth of lettuce main roots are suppressed in low pH. Root hairs are induced on the almost all root epidermal cells grown in low pH to compensate the ability of root water uptake. In low pH, Mn uptake is reduced to 1/5. Elimination of Mn from neutral pH media induced root hair-formation like as low pH. On the other hand, addition of excess Mn in low pH media suppresses root hair formation. We determined role of Mn in low pH induced root hair-formation more precisely in this research.Rate and position of Mn uptake were determined using radioactive ^<54>Mn. Rate of Mn uptake was reduced to about 1/3 within 1 hr after lowering of medium pH. Time-course and position of root hair-formation which was induced by elimination of Mn from neutral pH medium were similar to those were induced by low pH. These results indicated that low pH induced reduction of Mn uptake ability was the cause of root hair initiation in lettuce seedlings (Konno, M. et al. 2006).To make clear Mn transporter(s) in lettuce, we constructed an yeast mutant strain which lacked two Mn transporter. Transformation of putative lettuce Mn transporter gene(Ls-MDR1) to the yeast mutant could not rescue Mn requirement of the mutant. Transformation of lettuce genes to the mutant by so called shot-gun method showed one candidate of Mn transporter gene.Application of H^+ pump inhibitor vanadate could induce root hair formation in neutral pH. This results indicated the possibility that low pH at first affected on the H+ pump ability then Mn uptake was reduced by the decrease of H+ pump ability.

生菜主要根部的生长在低pH值中被抑制。在低pH中生长的几乎所有根表皮细胞都会诱导根毛，以补偿根水吸收的能力。在低pH值中，MN吸收降低至1/5。从中性pH培养基中消除Mn诱导的根部毛发型，例如低pH。另一方面，在低pH培养基中添加过量的MN抑制了根部头发的形成。在这项研究中，我们更精确地确定了Mn在低pH诱导的根部胶质形成中的作用。使用放射性 ^<54> MN确定Mn摄取的率和位置。降低中pH值后，在1小时内将MN摄取率降低至约1/3。通过从中性pH培养基中消除Mn诱导的根部毛发的时间顺序和位置与低pH值相似。这些结果表明，低pH值诱导的Mn摄取能力的降低是生菜幼苗中根毛的原因（Konno，M。等，2006）。为了使莴苣中的清晰的Mn转运蛋白（S）在生菜中，我们构建了一种缺少两个MN转运蛋白的酵母突变株。推定的生菜MN转运蛋白基因（LS-MDR1）转化为酵母突变体无法挽救突变体的MN要求。通过所谓的射击方法将生菜基因转化为突变体，显示了Mn转运蛋白基因的一个候选者。H^+泵抑制剂脱氧酸盐的涂抹可以诱导中性pH中的根毛形成。该结果表明，首先会影响H+泵能力的低pH值，然后通过降低H+泵能力来降低MN吸收。

项目成果

Temporal and positional relationships between Mn uptake and low-pH-induced root hair formation in Lactuca sativa L, cv, Grand Rapids seedlings.

大急流城莴苣 (Lactuca sativa L, cv) 幼苗中锰吸收与低 pH 诱导的根毛形成之间的时间和位置关系。

• 期刊: J.Plant Res. (in press)
• 作者: Konno;M.;Ohishi;M.;Inoue;Y.
• 通讯作者: Y.

Temporal and positional relationships between Mn uptake and low-pH-induced root hair formation in Lactuca sativa L., cv Grand Rapids seedlings.

莴苣 (Lactuca sativa L., cv Grand Rapids) 幼苗中锰吸收与低 pH 诱导的根毛形成之间的时间和位置关系。

• 发表时间: 2006
• 期刊: J. Plant Res. in press
• 作者: Konnno;M.;Ohishi;M.;Inoue;Y.
• 通讯作者: Y.

Temporal and positional relationships between Mn uptake and low-pH-induced root hair formation in Lactuca sativa L., cv, Grand Rapids seedlings.

大急流城莴苣 (Lactuca sativa L., cv) 幼苗中锰吸收与低 pH 诱导的根毛形成之间的时间和位置关系。

• 发表时间: 2006
• 期刊: J.Plant Res. 119(in press)
• 作者: Konno;M.;Ohishi;M.;Inoue Y.
• 通讯作者: Inoue Y.