Upland rice and lowland rice exhibited different PIP expression under water deficit and ABA treatment

Abstract

Aquaporins play a significant role in plant water relations. To further understand the aquaporin function in plants under water stress, the expression of a subgroup of aquaporins, plasma membrane intrinsic proteins (PIPs), was studied at both the protein and mRNA level in upland rice (Oryza sativa L. cv. Zhonghan 3) and lowland rice (Oryza sativa L. cv. Xiushui 63) when they were water stressed by treatment with 20% polyethylene glycol (PEG). Plants responded differently to 20% PEG treatment. Leaf water content of upland rice leaves was reduced rapidly. PIP protein level increased markedly in roots of both types, but only in leaves of upland rice after 10 h of PEG treatment. At the mRNA level, OsPIP1;2, Os-PIP1;3, OsPIP2;1 and OsPIP2;5 in roots as well as OsPIP1;2 and OsPIP1;3 in leaves were significantly up-regulated in upland rice, whereas the corresponding genes remained unchanged or down-regulated in lowland rice. Meanwhile, we observed a significant increase in the endogenous abscisic acid (ABA) level in upland rice but not in lowland rice under water deficit. Treatment with 60 µM ABA enhanced the expression of OsPIP1;2, OsPIP2;5 and OsPIP2;6 in roots and OsPIP1;2, OsPIP2;4 and OsPIP2;6 in leaves of upland rice. The responsiveness of PIP genes to water stress and ABA were different, implying that the regulation of PIP genes involves both ABA-dependent and ABA-independent signaling pathways during water deficit.

Root development and the expression of aquaporin genes in rice seedlings under osmotic stress

“…Previous studies have reported the effects of osmotic stress on the expression of aquaporin genes and the genotypic difference in the response of aquaporin gene expression to osmotic stresses (Guo et al, 2006;Lian et al, 2006). However, the study is limited to evaluation of the relationship between aquaporin gene expression that the response of root development to osmotic stress was different in the two cultivars.…”

“…Recent studies have reported that aquaporins facilitate water transport in plant tissues in many plant species (Knipfer et al, 2011;Mahdieh et al, 2008;Murai-Hatano et al, 2008;Sakurai et al, 2008). The regulation of aquaporin gene expression, their trafficking and/or their reversible gating actively regulate the water movement in the plant and play an important role in drought resistance and/or recovery from drought (Matre et al, 2002;Tournaire-Roux et al, 2003;Lian et al, 2006;Guo et al, 2006;Hachez et al, 2013;Luu & Maurel, 2013). These studies indicate that aquaporin OPEN ACCESS previous studies (Sakurai et al, 2005;Sakurai-Ishikawa et al, 2011).…”

The Role of Tobacco Aquaporin1 in Improving Water Use Efficiency, Hydraulic Conductivity, and Yield Production Under Salt Stress

“…However, while overexpression of stress-induced AQPs resulted in improving the plant's stress resistance, expressing AQPs that are down-regulated under abiotic stress had the opposite effect. For example, the rice (Oryza sativa) PIP1 AQP OsPIP1;3 is a stress-induced gene that increases its transcript level in both leaves and roots of the stress-resistant upland rice (subspecies indica cv Zhonghan 3) in response to stress (Lian et al, 2004(Lian et al, , 2006. Overexpressing OsPIP1;3 in the stress-sensitive lowland rice (subspecies japonica cv Zhonghua 11) improved its water status during conditions of water deficit and revealed an increase in whole-plant transpiration and L p (Lian et al, 2004).…”

Molecular cloning and expression of drought-induced protein 3 (DIP3) encoding a class III chitinase in upland rice

“…Upland rice (Oryza sativa) was germinated in the dark for 3 days at 28°C, and the seedlings grown in nutrient solution at a photon flux density of 300-350 mol m-2s-1, with 60-80% relative humidity,12-h light/12-h dark day-night cycle and 28°C temperature in a phytotron (Lian et al, 2006). Four-week-old plants were used for the different treatments.…”