Os01g0194300

The rice Os01g0194300 was reported as NH1 in 2005 by researchers from U.S.A.

Gene Symbol

• Os01g0194300 <=> OsNH1, OsNPR1, OsNPR1/NH1, NPR1, OsPR2, PR2

Function

• NH1 may be involved in the regulation of SA in response to environmental changes.
• OsNPR1(also called NH1) may also play a central role in herbivoreinduced rice defense responses.

Expression

• Transgenic rice plants overexpressing OsNH1 (NH1ox) acquire high levels of resistance to Xanthomonas oryzae pv. oryzae. The resistance phe- notype is heritable and correlates with the presence of the transgene and reduced bacterial growth.
• Northern analysis shows that NH1ox rice spontaneously activates defense genes, contrasting with NPR1-overexpressing Arabidopsis, where defense genes are not activated until induction.
• Wild-type NH1, but not a point mutant corresponding to npr1-1, interacts strongly with the rice transcription factor rTGA2.2 in yeast two-hybrid. Greenhouse-grown NH1ox plants develop lesion-mimic spots on leaves at preflowering stage although no other developmental effects are observed.
• However, when grown in growth chambers (GCs) under low light, NH1ox plants are dwarfed, indicating elevated sensitivity to light.
• The GC-grown NH1ox plants show much higher salicylic acid (SA) levels than the wild type, whereas greenhouse-grown NH1ox plants contain lower SA.

Evolution

• The role of OsNPR1 in plant defense response is similar to the role of AtNPR1but not the role ofNaNPR1. This finding is consistent with the result that At NPR1 is more homologous to OsNPR1 than is NaNPR1 in evolution and biochemistry. rice had a NPR1-mediated disease-resistance pathway similar to Arabidopsis.

Labs working on this gene

• Department of Plant Pathology, University of California, Davis 95616, U.S.A.; 2 United States Department of Agriculture-Agricultural Research Service, Prosser, WA 99350, U.S.A.