Nutrient dynamic and transfer characteristics of trees reflect the preservation and utilization of nutrients,and the adaptability to the infertile soil and environment.The change of nutrient content and the transfer ratio of element N,P,K,Ca,Mg in living and fallen leaves of three Eucalyptus varieties of 184-1,201-2,guanglin-9 were measured and analyzed.The results indicated that the content of N,P,K,Ca,Mg in leaves was significantly different monthly within a year.In general,the nutrient content and the transfer rate of the leaf were relatively higher in the growing season（6-10 months）than that in other seasons.The nutrient content in the living leaves was significantly higher than that of the fallen ones,and the nutrient content in the living leaves was positively correlated（r=0.94,P<0.01）with that in the fallen ones.The nutrient content and the transfer ratio were different among the three varieties of eucalyptus.Contents of N and Ca were the highest in 184-1,and contents of P,K,Mg were the highest in 201-2,while contents of the other four elements except N were the lowest in Guanglin-9.In terms of the nutrient transfer rate,Ca had no change,and the rate of the other four elements was P>N>K>Mg and the difference was significantly different（F=192.19,P<0.01）.The nutrient content of the leaf was significantly(t=2.97> t 0.025 6=2.446 9),however the nutrient transfer rate was not remarkably affected by fertilization.There was no significant difference in the nutrient transfer rate among the three Eucalyptus varieties.The results showed that the changes of leaf nutrient content and the transfer rate were related with many factors,such as growth characteristics and biological characteristics of species and external conditions.
【目的】克隆84K杨水杨酸结合蛋白2(Salicylic acid-binding protein 2,SABP2)基因并预测其功能。【方法】以生长至5片小叶的84K杨组培苗为材料,提取其叶和茎的总RNA。根据毛果杨SABP2基因(GenBank序列号:XM_002310718.2)的完整CDs序列,设计84K杨SABP2基因的引物,采用RT-PCR技术扩增84K杨SABP2基因全长,然后连接到pGM-T克隆载体,转化大肠杆菌TOP10感受态细胞,对84K杨SABP2基因进行克隆,获得该基因的全长序列。通过各种在线软件对84K杨SABP2基因及其编码的蛋白质进行生物信息学分析。【结果】84K杨基因的cDNA序列全长822bp,开放阅读框789bp,编码263个氨基酸。生物信息学分析表明,84K杨SABP2与毛白杨SABP2(GenBank序列号:JQ086570.1)的同源性最高,达98%;84K杨SABP2基因位于微体中;SABP2蛋白有11个蛋白质结合位点,属于α/β折叠水解酶家庭成员中的酯酶,为亲水性蛋白。【结论】成功克隆了84K杨的SABP2基因,其功能与前人对草本植物中SABP2部分功能的研究结果一致。
