Molecular cloning and characterization of CeTIP1;1,a gene encoding tonoplast intrinsic protein from Cyperus esculentus tubers
Tonoplast intrinsic proteins (TIPs),which constitute a subfamily of aquaporin facilitating the move-ment of water at vacuolar membranes,play a key role in growth,development,and stress response of plants. Tiger-nut (Cyperus esculentus),which initially originated in Africa and Mediterranean,is a novel herbaceous oil crop uniquely accumulating high levels of oil in underground tubers. Based on available genome and transcriptome data,in this study,a tuber-abundant TIP gene named CeTIP1;1 was cloned and characterized. This gene was shown to possess two introns with a coding sequence of 756 bp,putatively encoding 251 amino acids with the molecular weight of 25.75 kDa,the isoelectric point of 6.01,the instability index of 24.90,the grand average of hydropathicity of 0.831,and the aliphatic index of 107.77,implying its stable,acidic,and hydrophobic features. The protein in-cludes one conservative major intrinsic protein (MIP) domain specific to aquaporins. Phylogenetic analysis indicated that CeTIP1;1 clusters with OsTIP1;1 and exhibits a relatively high sequence similarity of 92.83％,supporting that it is a TIP1 homolog. Subcellular localization analysis showed that CeTIP1;1 was indeed localized to the vacuolar membrane of Nicotiana tabacum leaves. Expression analysis revealed a constitutive and high level expression of Ce-TIP1;1 in all tissues examined in this study. Moreover,CeTIP1;1 was shown to exhibit a bell-like expression pat-tern during tuber development. These results laid a solid foundation for further uncovering the mechanism of water balance in tigernut tubers.
万方数据
维普
