抄録
Arabidopsis thaliana possesses three types of hemoglobin (Hb) genes: class I, class II, and truncated Hb (trHb). AtGLB3 is a homologe of trHb that are widely distributed in lower organisms such as bacteria and unicellular eukaryotes. The function of AtGLB3 in vivo has remained unknown. The T-DNA insertion mutant ΔGLB3 lacks the functional gene of the trHb. We have found that ΔGLB3 cannot germinate above 32ºC where the wild type shows normal germination. The mutant is extremely sensitive to high temperature stress during germination. The germination was partially restored by adding carboxy-PTIO, a nitric oxide (NO) scavenger, chlorogenic acid or bovine serum Hb. Furthermore, the volatile organic compound isoprene also restored the germination capability of ΔGLB3 at high temperature. This strongly suggests that the failure of ΔGLB3 to germinate at high temperature is caused by NO scavenging activity and physiological function of ΔGLB3 have been first reported in this paper.
