A Lily ASR Protein Involves Abscisic Acid Signaling and Confers Drought and Salt Resistance in Arabidopsis

Abstract

LLA23, an abscisic acid-, stress-, and ripening-induced protein, was previously isolated from lily (Lilium longiflorum) pollen. The expression of LLA23 is induced under the application of abscisic acid (ABA), NaCl, or dehydration. To provide evidence on the biological role of LLA23 proteins against drought, we used an overexpression approach in Arabidopsis (Arabidopsis thaliana). Constitutive overexpression of LLA23 under the cauliflower mosaic virus 35S promoter confers reduced sensitivity to ABA in Arabidopsis seeds and, consequently, a reduced degree of seed dormancy. Transgenic 35STLLA23 seeds are able to germinate under unfavorable conditions, such as inhibitory concentrations of mannitol and NaCl. At the molecular level, altered expression of ABA/stress-regulated genes was observed. Thus, our results provide strong in vivo evidence that LLA23 mediates stress-responsive ABA signaling. In vegetative tissues, it is intriguing that Arabidopsis 35STLLA23 stomata remain opened upon drought, while transgenic plants have a decreased rate of water loss and exhibit enhanced drought and salt resistance. A dual function of the lily abscisic acid-, stress-, and ripening-induced protein molecule is discussed.

The ZmASR1 Protein Influences Branched-Chain Amino Acid Biosynthesis and Maintains Kernel Yield in Maize under Water-Limited Conditions

“…ASR overexpression studies in plants are exemplified by works carried out on Solanoideae (Kalifa et al, 2004b;Frankel et al, 2007) and Arabidopsis, although the latter does not include any ASR homologous genes (Yang et al, 2005;Liu et al, 2010). Our study demonstrated that ZmASR1-OE improved the kernel yield of transgenic maize in the field under well-watered and water-limited conditions.…”

“…These associations were validated by the observation that transgenic maize lines misexpressing ZmASR1 showed significant changes in leaf senescence under mild water deficit conditions in the field (Jeanneau et al, 2002). Interestingly, transgenic Arabidopsis (Arabidopsis thaliana) plants overexpressing an ASR gene from Lilium longiflorum (LLA23) or banana (Musa paradisiaca; MpASR) exhibited enhanced capacity to survive in water-limited conditions (Yang et al, 2005;Liu et al, 2010). Overexpression of the tomato (Solanum lycopersicum) ASR1 gene (SlASR1) in tobacco (Nicotiana tabacum) plants also resulted in decreased rates of water loss (Kalifa et al, 2004b).…”

“…On the basis of such findings, these ASR proteins have been proposed to regulate the transcription of sugarand abiotic stress-regulated genes in fruit and vegetative tissues, respectively (Cakir et al, 2003;Kalifa et al, 2004b;Frankel et al, 2007;Saumonneau et al, 2008). However, a dual function of LLA23 and SlASR1 proteins as a regulator and a protective molecule upon water deficit has also been proposed (Yang et al, 2005Konrad and Bar-Zvi, 2008).…”

Rice ASR1 Protein with Reactive Oxygen Species Scavenging and Chaperone-like Activities Enhances Acquired Tolerance to Abiotic Stresses in Saccharomyces cerevisiae

“…For example, over-expression of tomato ASR1 and lily ASR increases salt tolerance in tobacco (Kalifa, 2004) and Arabidopsis (Yang et al, 2005), respectively. ASR1-overexpressing transgenic (TG) tobacco plants showed increased expression of different genes encoding NAD + -dependent malate dehydrogenase, proline-rich protein, secretory peroxidase, lipid transfer protein, fructose biphosphate aldolase (Fbap), raffinose synthase, chloroplast ATPase, 4-coumarate-coenzyme A ligase, and NADP + -dependent ferredoxin reductase under salt stress conditions.…”

“…Abscisic acid-, stress-, and ripening-induced (ASR) proteins are small and heat-stable proteins that have a high hydrophilicity and act as downstream components of a common transduction pathway for sugar (Yang et al, 2005). Among ASR proteins, ASR1 is a plant-specific, highly charged low molecular weight and heat-stable protein whose expression in plants is induced by high salinity, dehydration, and treatment with the plant hormone ABA (Goldgur et al, 2007).…”