论文部分内容阅读
磷是柑橘生长发育过程中必需的元素.在拟南芥中PHT1家族成员至少介导了植株根部95％以上的磷吸收过程,至今已在水稻、油茶和杨树等多种植物中发现了具有相似功能的PHT1基因,说明PHT1基因在植物的磷吸收过程具有重要作用及在植物进化过程中具有保守性.本研究从柑橘基因组序列信息中分析出7个柑橘PHT1基因,其中在根部表达较强的基因Cs3g27660编码产物与AtPHT1;8(或AtPHT1;9)的蛋白序列相似性最高;而Cs9g10540、Cs5g29860、Cs9g10530与AtPHT1;1(或AtPHT1;4)的蛋白序列相似性最高,并且三者均能在根部表达及表达受低磷胁迫诱导,亚细胞定位结果亦显示三者均能定位在细胞的质膜上,推测Cs9g10540、Cs9g10530、Cs5g29860可能为柑橘中类AtPHT1;J(或AtPHT1;4)基因.“,”Phosphorus is an essential element for Citrus growth and development.PHT1 transporters mediate more than 95％ of the phosphate acquisition in Arabidopsis.PHT1 genes have also been found in rice,oil tea,poplar,et al.,which suggested they plays an important role in the process of phosphorus uptake,and may be conservative in plant evolution.This study screened 7 PHT1 genes in Citrus.Compared with other PHT1 genes in Citrus sinensis,the transcript levels of Cs3g27660 was higher in roots,and amino acid sequence analysis showed Cs3g27660 displayed the highest similarity with A tPHT1;8 (or A tPHT1;9).While Cs9g10540,Cs9g10530,Cs5g29-860 and A tPHT1;1 (or A tPHT1;4) exhibited the highest homology,which can also express in roots and their transcriptions increased significantly during growth in low phosphorus conditions.Subcellular localization tests showed that all the three genes can target to the plasma membrane.These suggested Cs9g10540,Cs9g10530,Cs5g29860 may be A tPHT1;1 (or A tPHT1;4)-like gene in Citrus.