Cloning Of BOR Gene Family Members And Aquaporingenes(SIP And NIP) And Their Response To Boron Deficiency In Poncirus Trifoliate(L). RAF.

Boron deficiency of soil in citrus production areas of China is common. Boron is absorbed by roots and then transported to other tissues. But the mechanism of boron absorbtion and transport is still unknown. Previous researches have shown that BOR gene family members and Aquaporin genes are related to boron transport. Here we want to clear that if BOR gene family and Aquaporin genes participate in boron transport in citrus.Poncirus trifoliata(L.) RAF. was used as material in this research, BOR gene family members and Aquaporin genes(SIP and NIP) were cloned and analyzed by bioinformatics, their m RNA levels in boron deficiency were measured. The results are in the following:1. Five BOR gene family members were cloned: Ptr BOR1, Ptr BOR2, Ptr BOR3, Ptr BOR4 and Ptr BOR5. Ptr BORs encode large molecular weight proteins whose p I are high. Multiple sequence alignment shows that Ptr BOR1, Ptr BOR2 and Ptr BOR3 have the conserved endocytosis degredation and polar orientation residues. Phylogenetic tree separates Ptr BORs to two subgroups: Ptr BOR1, Ptr BOR2 and Ptr BOR3 belong to one subgroup and Ptr BOR2 and Ptr BOR3 belong to another subgroup.2. Eight Aquaporin genes(SIP and NIP) were cloned. Ptr SIP1-1, Ptr SIP1-2 and Ptr SIP2-1 are SIP gene family members and Ptr NIP1-2, Ptr NIP4-1, Ptr NIP4-2, Ptr NIP5-1 and Ptr SIP6-1 are NIP gene family members. Ptr SIPs and Ptr NIPs encode small molecular weight proteins whose p I are high. Ptr SIPs and Ptr NIPs have the characteristic NPA residues of Aquaporins and conserved residues which decide the substrate of transport. Ptr SIPs and Ptr NIPs are at both ends of Phylogenetic tree, Ptr SIP1-1 and Ptr SIP1-2 belong to SIP1 s subgroup and Ptr SIP2-1 belongs to SIP2 s.3. Ptr BOR4 mainly expressed in leaves, the other Ptr BORs mainly expressed in roots. The expression of Ptr BORs changed differently in boron deficiency. Among them, the expression of Ptr BOR1 upgraded in roots and leaves, the expression of Ptr BOR2 upgraded in roots and downgraded in stems, and the expression of Ptr BOR3 upgraded in roots, stems and leaves.4. Ptr SIPs and Ptr NIPs expressed in all tissues. Ptr SIP1-2, Ptr SIP2-1 and Ptr NIP4-1 mainly expressed in roots. Ptr NIP6-1 mainly expressed in stems. Ptr NIP1-2 and Ptr NIP5-1 mainly expressed in roots and stems. Ptr SIP1-1 and Ptr NIP4-2 mainly expressed in stems and leaves. The expression of Ptr SIPs and Ptr NIPs changed severely in boron deficiency. Among them, the expression of Ptr SIP2-1 upgraded in roots and leaves and downgraded then upgraded in stems, the expression of Ptr NIP5-1 upgraded in roots, stems and leaves, the expression of Ptr NIP6-1 upgraded in stems and leaves.