A Lily ASR protein involves abscisic acid signaling and confers drought and salt resistance in Arabidopsis.
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 35SLLA23 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 35SLLA23 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.
Yang
Chin-Ying
CY
Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.
Chen
Yu-Chuan
YC
Jauh
Guang Yuh
GY
Wang
Co-Shine
CS
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D027762:Lilium / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology
D018744:DNA, Plant; C413484:LLA23 protein, Lilium longiflorum; D010940:Plant Proteins; D011994:Recombinant Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid