Study Of The Adaptation Mechanism Of Pinus Elliottii ×p.caribaea Clones To P Starvation By Differentially Expressed Protein Profiling

Pinus elliottii × P.caribaea is one of the main species of forestry in South China with obvious advantages.Phosphorus is the vital element for plants growth and development,which is fixed in the soil and then it canno t be absorbed and utilized directly.Pinus elliottii × P.caribaea is dependent on the phosphorus efficiency.It is necessary for phosphorus efficiency improvement by using proteomics to screen the key proteins and pathways.The material of the trial was seedlings of 10 Pinus elliottii × P.caribaea clones cultured in sand with –P and +P treatments.According to the apperences of height and diameter,clone 31(tolerance to –P,no reaction to +P),clong 38(tolerance to –P,reaction to +P),clone 4(tolerance lower than 31 and 38,reaction to +P)were chosen for iTRAQ(isobaric tags for relative and abosolutely quantification).Totally,2074 reliable protein were identified from 5 batches of iTRAQ analysis,which showed the genotype-,treatment-,and the interaction regulation pattern by fold changes comparison among different groups in shoots and roots.In roots,1076 differentially expressed proteinsbetween treatments(tDEPs)were screened,and 347 of them were ovelapping in clone 4 and 31,while 110 9 DEPs among genotypes(cDEPs)were screened.In shoots,882 tDEPs were screened out and 151 of them were overlapping in clone 4,31 and 38,155 of them were overlapping in clone 4 and 31.The number of cDEPs in clone 4 and 31 was 800,in clone 38 and 31 was 738.The up-regulated and down-regulated patterns were obviously different among different groups,the up-regulated tDEPs were more abundent.Especially,the clonal rank of the difference between up-and down-regulated tDEPs were clone 4>clone 38>clone 31.In Gene Onology of roots,DEPs' percentage in –P31/+P31 was higher than that in –P4/+P4,which were abundanted in the photosynthesis,oxidation-reduction process,thioester metabolic process,DEPs' percentage in –P31/+P31 was higher than that in –P4/+P4,which were abundanted in thericarboxylic acid cycle?organic acid metabolic process ? cellular nitrogen compound metabolic process.In Gene Onology,DEP ' s percentage in –P31/+P31 and –P38/+P38 were abundanted in tricarboxylic acid cycle,and small molecule metabolic process,phosphorus metabolic process and oxidation-reduction process.The KEGG Pathway annotation on the DEPs from different groups showed that the tDEPs were abundantly involved in carbohydrate andenergy metabolism.In the level of carbohydrate metabolism,DEPs' percentage from shoots and roots with-P regulated were highly abuntanted in glycolysis/gluconeogenesis metabolism,especially –P31/+P31 was dramaticly higher than –P4/+P4 in roots.DEPs' percentage of Glytoxaklic acid and dicarboxylic in –P4/-P31 and +P4>+P31were much higher than the last one.In physiological trial,it was observed that treatment had a significant effect on the concerntration of soluble phosphorus and protein,the clone had a significant effect on the concerntration of soluble phosphorus andprotein,and specific activity for acidphosphatase,while the interaction effect of treatment and clone had a significient effect only on the soluble phosphorusand specific activity for acidphosphatase in roots.