Chen Zhi Chang, Liao Hong
Root Biology Center, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China.
Root Biology Center, Fujian Agriculture and Forestry University, Fujian, Fuzhou 350002, China.
J Genet Genomics. 2016 Nov 20;43(11):631-638. doi: 10.1016/j.jgg.2016.11.003. Epub 2016 Nov 11.
Aluminum (Al) toxicity and phosphorous (P) deficiency are two major limiting factors for plant growth on acidic soils. Thus, the physiological mechanisms for Al tolerance and P acquisition have been intensively studied. A commonly observed trait is that plants have developed the ability to utilize organic acid anions (OAs; mainly malate, citrate and oxalate) to combat Al toxicity and P deficiency. OAs secreted by roots into the rhizosphere can externally chelate Al and mobilize phosphate (Pi), while OAs synthesized in the cell can internally sequester Al into the vacuole and release free Pi for metabolism. Molecular mechanisms involved in OA synthesis and transport have been described in detail. Ensuing genetic improvement for Al tolerance and P efficiency through increased OA exudation and/or synthesis in crops has been achieved by transgenic and marker-assisted breeding. This review mainly elucidates the crucial roles of OAs in plant Al tolerance and P efficiency through summarizing associated physiological mechanisms, molecular traits and genetic manipulation of crops.
铝（Al）毒性和磷（P）缺乏是酸性土壤上植物生长的两个主要限制因素。因此，人们对植物耐铝性和磷吸收的生理机制进行了深入研究。一个普遍观察到的特征是，植物已经发展出利用有机酸阴离子（OAs；主要是苹果酸、柠檬酸和草酸）来对抗铝毒性和磷缺乏的能力。根系分泌到根际的有机酸阴离子可以在外部螯合铝并活化磷酸盐（Pi），而细胞内合成的有机酸阴离子可以在内部将铝隔离到液泡中，并释放游离的Pi用于代谢。参与有机酸阴离子合成和运输的分子机制已得到详细描述。随后通过转基因和标记辅助育种，通过增加作物中有机酸阴离子的分泌和/或合成，在耐铝性和磷效率方面实现了遗传改良。本综述主要通过总结相关生理机制、分子特征和作物遗传操作，阐明有机酸阴离子在植物耐铝性和磷效率中的关键作用。
