Intracellular distribution and binding state of aluminum in root apices of two common bean (Phaseolus vulgaris) genotypes in relation to Al toxicity
Intracellular distribution and binding state of aluminum in root apices of two common bean (Phaseolus vulgaris) genotypes in relation to Al toxicity
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DOI：
10.1111/j.1399-3054.2008.01183.x
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发表时间：
2009-02-01
影响因子：
6.4
通讯作者：
Horst, Walter Johannes
中科院分区：
文献类型：
--
作者：
Rangel, Andres Felipe;Rao, Idupulapati Madhusudana;Horst, Walter Johannes
采用铝交换和铝分馏方法，研究了两种菜豆（Phaseolusvulgaris L.）不同基因型对铝的抗性不同。这两种基因型的特点是由一个类似的铝敏感性的初始期（4小时），然后由一个相反的恢复期（8-24小时）。一个较高的初始铝积累在Quimbaya（抗铝）在5毫米根尖相比，VAX-1（铝敏感）可能与其较高的含量的非甲基化果胶，从而更高的负电荷的细胞壁（CWs）。Al在根尖中的结合状态和细胞分布表明，根伸长速率与游离质外体和稳定结合的非柠檬酸可交换态CW Al呈显著负相关，而与共质体和活性结合态CW Al无显著相关。柠檬酸盐可交换CW Al。据推测，抗铝基因型Quimbaya从初始铝胁迫中诱导和持续恢复需要减少质外体中稳定结合的铝，从而使细胞伸长和分裂恢复。
The role of the intracellular distribution and binding state of aluminum (Al) in Al toxicity, using Al exchange and Al fractionation methodologies, were studied in two common bean (Phaseolus vulgaris L.) genotypes differing in Al resistance. These two genotypes are characterized by a similar initial period (4 h) of Al sensitivity followed by a contrasting recovery period (8-24 h). A higher initial Al accumulation in Quimbaya (Al resistant) in the 5-mm root apex compared with VAX-1 (Al sensitive) could be related to its higher content of unmethylated pectin and thus higher negative charge of the cell walls (CWs). The binding state and cellular distribution of Al in the root apices revealed that the root elongation rate was significantly negatively correlated with the free apoplastic and the stable-bound, not citrate-exchangeable CW Al representing the most important Al fraction in the root apex (80%), but not with the symplastic and the labile-bound, citrate-exchangeable CW Al. It is postulated that the induced and sustained recovery from the initial Al stress in the Al-resistant genotype Quimbaya requires reducing the stable-bound Al in the apoplast thus allowing cell elongation and division to resume.