Characterization of AQP gene expressions in Brassica napus during seed germination and in response to abiotic stresses

Abstract

Water transport across the cell membranes is regulated largely by a family of proteins known as aquaporins (AQPs). Plasma membrane intrinsic protein (PIP) is an important subfamily of plant AQPs localized on the plasma membrane. To investigate the molecular mechanism of water regulation in seed germination, seven genes encoding PIP were initially cloned and sequenced from the germinating seed cDNA pool of Brassica napus. They belong to the PIP1 and PIP2 subfamilies. The transcription of the seven cloned genes plus three previously identified AQP genes from B. napus were analyzed in different organs and different stages of seed germination by quantitative real-time PCR (qRT-PCR). The results show that the expressions of the ten AQP genes were lower or scarcely detected in dry seeds, but were up-regulated during germination as well as in young seedlings. In addition, the expression of these ten AQP genes in response to an abiotic stress during seed germination was investigated and the results also show differential responses to abiotic stress treatments. Our findings suggest that these ten genes play different roles during plant development and response to abiotic stresses in B. napus.

Genome-wide identification and characterization of the aquaporin gene family in Sorghum bicolor (L.)

“…AQP transcripts SbPIP1;6 and PIP2;1 were downregulated in all tested abiotic stress conditions but had higher expression in tissues including seedlings, roots and panicles. This type of diverse expression pattern of AQP transcripts in response to abiotic stresses has also been observed in recent studies (Ge et al, 2014;Jang et al, 2004;Mariaux et al, 1998;Wang et al, 2003;Weig et al, 1997;Yamada et al, 1997). These results indicate that AQPs play a major role in maintaining water homeostasis during plant responses to environmental stress (Jang et al, 2004).…”

“…AQPs are water channel proteins belonging to the membrane intrinsic proteins (MIPs) family that facilitate the rapid and selective transport of water and other small neutral solutes across plant cell membranes (Agre, 2006;Chaumont et al, 2001;Hachez and Chaumont, 2010). AQPs are present in most living organisms and are widely involved in different physiological processes, such as seed germination (Ge et al, 2014), reproduction (Bots et al, 2005), stoma movement (Siefritz et al, 2004;Uehlein and Kaldenhoff, 2008), photosynthesis Vera-Estrella et al, 2012), cell elongation (Higuchi et al, 1998), and responses to diverse abiotic stress treatments (Ehlert et al, 2009;Gomes et al, 2009;Luu and Maurel, 2005;Peng et al, 2007). Different AQP isoforms are targeted to distinct subcellular compartments and have emerged as important markers for plant cell membrane differentiation.…”

Molecular cloning and expression analysis of Aquaporin genes in pearl millet [ Pennisetum glaucum (L) R. Br.] genotypes contrasting in their transpiration response to high vapour pressure deficits

“…Aquaporins are small integral membrane water channeling proteins that belong to the ancient family of major intrinsic proteins (MIPs) and have been found in most living organisms, primarily in facilitating water transport [20][21][22]. AQPs are widely involved during different stages of plant development [23][24][25][26][27] and in response to diverse abiotic stresses [27][28][29][30][31]. Plant AQPs have distinct AQP isoforms that are targeted to their specific functions in response to different environmental conditions showing a high multiplicity of isoforms with 35, 33, 41, 41, 47 and 33 homologs in Arabidopsis, maize, sorghum, potato, tomato and rice, respectively [21,27,[32][33][34][35].…”

Genome-wide identification and characterization of aquaporin genes (AQPs) in Chinese cabbage (Brassica rapa ssp. pekinensis)

“…The number of AQP genes in plants is more diverse than in animals (Maurel et al 2008;Ahmad et al 2013). In plants, AQPs play extensive roles not only in seed germination (Gao et al 1999;Ge et al 2014), reproduction (Bots et al 2005), stoma movement (Siefritz et al 2004;Uehlein and Kaldenhoff 2008), photosynthesis (Uehlein and Kaldenhoff 2008;Vera-Estrella et al 2012), and cell elongation (Higuchi et al 1998), but also in response to diverse stresses (Luu and Maurel 2005;Peng et al 2007;Ishibashi et al 2011). With the boom in genome sequencing projects in plants, genome-wide analyses of AQP genes have revealed 1 3 that there are 35 AQP genes in Arabidopsis (Johanson et al 2001), more than 36 in maize (Chaumont et al 2001), about 34 in rice (Sakurai et al 2005;Nguyen et al 2013), and 55 in Populus (Gupta and Sankararamakrishnan 2009).…”