The rice ASR5 protein: a putative role in the response to aluminum photosynthesis disturbance.
Under acidic soil conditions, aluminum (Al) becomes available to plants, which must cope with its toxicity by mechanisms involving both internal and external detoxification. Rice is the most Al-tolerant among the crop species, with Al detoxification being managed by both mechanisms. Recently, we focused on ASR (Abscisic acid, Stress and Ripening) gene expression analyses and observed increased ASR5 transcript levels in roots and shoots in response to Al. In addition, ASR5 RNAi knock down plants presented an Al-sensitive phenotype. A proteomic approach showed that ASR5 silencing affected several proteins related to photosynthesis in RNAi rice shoots. Furthermore, an ASR5-GFP fusion in rice protoplasts revealed for the first time a chloroplast localization of this protein. Because it is well known that Al induces photosynthetic dysfunction, here we discuss the hypothesis that ASR5 might be sequestered in the chloroplasts as an inactive transcription factor that could be released to the nucleus in response to Al to regulate genes related to photosynthesis.
Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Rafael Augusto
RA
Arenhart
Rogério
R
Margis
Marcia
M
Margis-Pinheiro
D000535:Aluminum / Q000633:toxicity*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D012275:Oryza / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects*; D010940:Plant Proteins / Q000378:metabolism*; D011523:Protoplasts / Q000187:drug effects / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014170:Transformation, Genetic / Q000187:drug effects
D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000535:Aluminum