Expression and functional analysis of the rice plasma-membrane intrinsic protein gene family

Abstract

Plasma membrane intrinsic proteins (PIPs) are a subfamily of aquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 (OsPIP1-1) or OsPIP2 (OsPIP2-2) in wild-type Arabidopsis, showed enhanced tolerance to salt (100 mM of NaCl) and drought (200 mM of mannitol), but not to salt treatment of higher concentration (150 mM of NaCl). Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.

Proteomic changes in maize as a response to heavy metal (lead) stress revealed by iTRAQ quantitative proteomics

“…Plasma membrane intrinsic proteins (PIPs), a subfamily of aquaporins, can control the translocation of water across the membrane. Previous studies have reported that, in various plant species, gene expression and function of PIPs can be modulated by heavy metals such as cadmium, copper, and mercury (Guo et al, 2006). Expression of PsPIP2-1 showed an increasing trend after HgCl 2 [mercury (II) chloride] treatment in Pisum sativum (Beaudette et al, 2007), whereas copper stress genes encoding plasmalemma PIP were down-regulated under copper application in Populus deltoides roots (Guerra et al, 2009).…”

Disruption of the 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) gene results in albino, dwarf and defects in trichome initiation and stomata closure in Arabidopsis

“…The expression levels of different genes were standardized to the constitutive expression level of Tubulin2. In one real-time PCR experiment, at least three values were produced for each sample, as previously reported [67]. The relative expression level of each gene, corresponding to the expression level of Tubulin2, was calculated using the 2 −∆∆t method [68].…”

Effect of Kaolin and Fulvic Acid Antitranspirants on Tomato Plants Grown under Different Water Regimes

“…General downregulation of most aquaporin transcription was reported under salt-stress in roots of Arabidopsis and maize (Alexandersson et al, 2005;Boursiac et al, 2005;Maathuis et al, 2003). Even though there is an overall downregulation of aquaporin gene in response to dehydration there was also specific upregulation of certain PIP transcripts in rice and Arabidopsis leaves (Alexandersson et al, 2005;Guo et al, 2006). For example, two upregulated transcripts in Arabidopsis were specifically expressed in aerial parts (Alexandersson et al, 2005).…”

“…Various studies were conducted on water stressdependent expression of aquaporin genes (Maurel et al, 2002), especially the studies carried out on maize, rice, radish, and Arabidopsis. In these studies the expression of the whole aquaporin family was studied (Alexandersson et al, 2005;Boursiac et al, 2005;Guo et al, 2006;Jang et al, 2004;Lian et al, 2004;Maathuis et al, 2003;Suga et al, 2002;Zhu et al, 2005). General downregulation of most aquaporin transcription was reported under salt-stress in roots of Arabidopsis and maize (Alexandersson et al, 2005;Boursiac et al, 2005;Maathuis et al, 2003).…”