Genes that are uniquely stress regulated in salt overly sensitive (sos) mutants.
Repetitive rounds of differential subtraction screening, followed by nucleotide sequence determination and northern-blot analysis, identified 84 salt-regulated (160 mM NaCl for 4 h) genes in Arabidopsis wild-type (Col-0 gl1) seedlings. Probes corresponding to these 84 genes and ACP1, RD22BP1, MYB2, STZ, and PAL were included in an analysis of salt responsive gene expression profiles in gl1 and the salt-hypersensitive mutant sos3. Six of 89 genes were expressed differentially in wild-type and sos3 seedlings; steady-state mRNA abundance of five genes (AD06C08/unknown, AD05E05/vegetative storage protein 2 [VSP2], AD05B11/S-adenosyl-L-Met:salicylic acid carboxyl methyltransferase [SAMT], AD03D05/cold regulated 6.6/inducible2 [COR6.6/KIN2], and salt tolerance zinc finger [STZ]) was induced and the abundance of one gene (AD05C10/circadian rhythm-RNA binding1 [CCR1]) was reduced in wild-type plants after salt treatment. The expression of CCR1, SAMT, COR6.6/KIN2, and STZ was higher in sos3 than in wild type, and VSP2 and AD06C08/unknown was lower in the mutant. Salt-induced expression of VSP2 in sos1 was similar to wild type, and AD06C08/unknown, CCR1, SAMT, COR6.6/KIN2, and STZ were similar to sos3. VSP2 is regulated presumably by SOS2/3 independent of SOS1, whereas the expression of the others is SOS1 dependent. AD06C08/unknown and VSP2 are postulated to be effectors of salt tolerance whereas CCR1, SAMT, COR6.6/KIN2, and STZ are determinants that must be negatively regulated during salt adaptation. The pivotal function of the SOS signal pathway to mediate ion homeostasis and salt tolerance implicates AD06C08/unknown, VSP2, SAMT, 6.6/KIN2, STZ, and CCR1 as determinates that are involved in salt adaptation.
Gong
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Center for Plant Environmental Stress Physiology, 1165 Horticulture Building, Purdue University, West Lafayette, Indiana 47907-1165, USA.
Koiwa
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Cushman
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Ray
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A
Bufford
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Kore-eda
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Matsumoto
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TK
Zhu
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Cushman
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Bressan
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Hasegawa
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D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D018744:DNA, Plant; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D012965:Sodium Chloride / Q000494:pharmacology*
D018744:DNA, Plant; D012965:Sodium Chloride