Leaf developmental age controls expression of genes encoding enzymes of chlorophyll and heme biosynthesis in pea (Pisum sativum L)

摘要: The effects of leaf developmental age on the expression three nuclear gene families in pea (Pisum sativum L.) coding for enzymes chlorophyll and heme biosynthesis have been examined. steady-state levels mRNAs encoding aminolevulinic acid (ALA) dehydratase, porphobilinogen (PBG) deaminase, NADPH:protochlorophyllide reductase were measured by RNA gel blot quantitative slot-blot analyses foliar leaves embryos that had imbibed 12 to 18 h developing seedlings grown either total darkness or under continuous white light up 14 d after imbibition. Both ALA dehydratase PBG deaminase detectable embryonic leaves, whereas mRNA was not observed at this early stage. All products found increase approximately same extent primary during first 6 8 imbibition (postgermination) regardless whether plants white-light illumination. In dark-grown seedlings, highest message accumulation 10 postgermination, and, thereafter, a steady decline observed. light-grown biosynthetic inversely correlated with age, youngest, rapidly expanding containing levels. A corresponding enzyme protein also stages development darkness; however, maximal delayed relative peak accumulation. We although protochlorophyllide immediately imbibition, time course phototransformable form molecule coincided expression. studies which various ages subsequently transferred 24 48 h, effect changes be more pronounced later stages. These results suggest these genes likely those other pathway are control common regulatory mechanism. Furthermore, it appears light, but rather as yet unidentified endogenous factors, factors controlling development.