Boron Supply Enhances Aluminum Tolerance in Root Border Cells of Pea (Pisum sativum) by Interacting with Cell Wall Pectins.
Boron Supply Enhances Aluminum Tolerance in Root Border Cells of Pea (Pisum sativum) by Interacting with Cell Wall Pectins.
复制标题
硼供应通过与细胞壁果胶相互作用增强豌豆 (Pisum sativum) 根部边缘细胞的铝耐受性
DOI：
10.3389/fpls.2017.00742
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发表时间：
2017
影响因子：
5.6
通讯作者：
Yu M
中科院分区：
文献类型：
--
作者：
Li XW;Liu JY;Fang J;Tao L;Shen RF;Li YL;Xiao HD;Feng YM;Wen HX;Guan JH;Wu LS;He YM;Goldbach HE;Yu M
铝毒是酸性土壤上限制作物生长的主要因素。硼（B）在植物中消除了铝的毒性，这主要被认为是由于形成鼠李糖半乳糖醛酸聚糖II-B（RGII-B）复合物，其有助于稳定细胞骨架。目前尚不清楚这是否是由于净负电荷的增加和/或进一步的机制。以豌豆（Pisumsativum）根缘细胞（RBC）的完整细胞、细胞壁和果胶为材料，研究了Al的积累和吸附动力学，以揭示B与碱溶性和螯合剂溶性果胶相互作用提高RBC耐Al性的机理。结果表明，B可通过在细胞壁中积累更多的铝来拯救红细胞免于铝诱导的细胞死亡，主要是在碱溶性果胶中。硼还促进Al 3+吸附和抑制Al 3+从碱溶性果胶的解吸。因此，更多的Al 3+被固定在碱溶性果胶级分内，而更少的Al 3+被固定在螯合剂溶性果胶内，使得Al 3+的移动的更少。硼诱导RG-II（KDO，2-keto-3-deoxyoctonic acid）含量增加，形成更多的硼酸盐-RGII复合物，并减少果胶的甲酯化反应，从而产生更多的负电荷，从而使细胞壁果胶中的Al ~（3+）还原。研究结果表明，充足的B供应有利于Al在碱溶性果胶中的固定，从而减少了Al 3+从外界进入共质体的机会。
Aluminum (Al) toxicity is the primary factor limiting crop growth in acidic soils. Boron (B) alleviates Al toxicity in plants, which is mainly considered to be due to the formation of Rhamnogalacturonan II-B (RGII-B) complexes, which helps to stabilize the cytoskeleton. It is unclear yet whether this is due to the increasing of net negative charges and/or further mechanisms. Kinetics of Al accumulation and adsorption were investigated using entire cells, cell wall and pectin of root border cells (RBCs) of pea (Pisum sativum), to reveal the mechanism of B in interacting with alkali-soluble and chelator-soluble pectin for an increased Al tolerance in RBCs. The results show that B could rescue RBCs from Al-induced cell death by accumulating more Al in the cell wall, predominately in alkali-soluble pectin. Boron also promotes Al3+ adsorption and inhibits Al3+ desorption from alkali-soluble pectin. Thus, more Al3+ is immobilized within the alkali-soluble pectin fraction and less in the chelator-soluble pectin, rendering Al3+ less mobile. Boron induces an increase of RG-II (KDO,2-keto-3-deoxyoctonic acid) content for forming more borate-RGII complexes, and the decrease of pectin methyl-esterification, thus creates more negative charges to immobilize Al3+ in cell wall pectin. The study provides evidence that abundant B supply enhances the immobilization of Al in alkali-soluble pectin, thus most likely reducing the entry of Al3+ into the symplast from the surroundings.