Salt-responsive genes in rice revealed by cDNA microarray analysis.
We used cDNA microarrays containing approximately 9,000 unigenes to identify 486 salt responsive expressed sequence tags (ESTs) (representing approximately 450 unigenes) in shoots of the highly salt-tolerant rice variety, Nona Bokra (Oryza sativa L. ssp. Indica pv. Nona). Some of the genes identified in this study had previously been associated with salt stress. However the majority were novel, indicating that there is a great number of genes that are induced by salt exposure. Analysis of the salt stress expression profile data of Nona provided clues regarding some putative cellular and molecular processes that are undertaken by this tolerant rice variety in response to salt stress. Namely, we found that multiple transcription factors were induced during the initial salt response of shoots. Many genes whose encoded proteins are implicated in detoxification, protectant and transport were rapidly induced. Genes supporting photosynthesis were repressed and those supporting carbohydrate metabolism were altered. Commonality among the genes induced by salt exposure with those induced during senescence and biotic stress responses suggests that there are shared signaling pathways among these processes. We further compared the transcriptome changes of the salt-sensitive cultivar, IR28, with that of Nona rice. Many genes that are salt responsive in Nona were found to be differentially regulated in IR28. This study identified a large number of candidate functional genes that appear to be involved in salt tolerance and further examination of these genes may enable the molecular basis of salt tolerance to be elucidated.
Chao
Dai Yin
DY
National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, China.
Luo
Yong Hai
YH
Shi
Min
M
Luo
Da
D
Lin
Hong Xuan
HX
D015152:Blotting, Northern; D002241:Carbohydrates / Q000096:biosynthesis; D016922:Cellular Senescence; D004260:DNA Repair; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D017136:Ion Transport; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D010770:Phosphotransferases / Q000096:biosynthesis / Q000235:genetics; D010788:Photosynthesis; D018749:RNA, Plant / Q000032:analysis; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
D002241:Carbohydrates; D018749:RNA, Plant; D014157:Transcription Factors; D012965:Sodium Chloride; D010770:Phosphotransferases