Phytochrome-initiated fast rhythm controlling developmental response

摘要: To identify the steps controlling a developmental response, we must relate changes occurring soon after inducing signal to responses many hours later. In higher plants exposure red light shifts patterns by converting phytochrome, ubiquitous plant pigment, into its active form1. Far converts phytochrome back original form and stops response. Red induces in electrical properties of 15–30s (refs 2, 3) within minutes ATP levels4, NADP transport5, nitrate reductase activity6 change. It requires or even days for effects on circadian rhyythms7, germination, de-aetiolation, flowering appear1. Until now there has been no indication mechanism which events immediately following conversion determine later development. should be possible probe nature first perturbing these thus affecting growth. If directly are sensitive additional light, then second illumination will alter overall We have found that brief flash given dark-grown bean seedlings starts oscillations temperature-compensated system. The interaction this system with showed oscillating controls subsequent