The chloroplast and leaf developmental mutant, pale cress, exhibits light-conditional severity and symptoms characteristic of its ABA deficiency

TY - JOUR

T1 - The chloroplast and leaf developmental mutant, pale cress, exhibits light-conditional severity and symptoms characteristic of its ABA deficiency

AU - Holding, D R

AU - Springer, P S

AU - Coomber, S A

PY - 2000

Y1 - 2000

N2 - The PALE CRESS gene (PAC) is essential for proper chloroplast and leaf development in Arabidopsis thaliana. The ability of pac mutants to accumulate significantly more chlorophyll when grown in low light conditions than in high light conditions suggests that carotenoid deficiency is at least partly responsible for premature cessation of chloroplast development. In addition to accumulation of low levels of chlorophyll and carotenoid pigments, pac mutants are abscisic acid (ABA) deficient and have characteristics which may be explained by this deficiency. These include reduced seed viability and, in enclosed growth conditions, increased leaf growth. Plants transformed with an antisense PAC construct often bear viviparous embryos which may be symptomatic of a deficiency in ABA. Since carotenoids are precursors of ABA, a role for PAC in carotenoid biosynthesis is further supported. The nuclear-encoded. chloroplast-localized PAC protein has been implicated in the maturation of plastid-encoded mRNAs. Thus, PAC may affect the abundance of one or more chloroplast proteins which function in the synthesis or stability of carotenoids. Using the PROLIFERA gene as a marker for cell division, it is shown that cell division profiles in the pac shoot apex are disrupted. pac leaves are relatively normal in size and shape despite the light intensity-induced variability of leaf cell defects, (C) 2000 Annals of Botany Company.

AB - The PALE CRESS gene (PAC) is essential for proper chloroplast and leaf development in Arabidopsis thaliana. The ability of pac mutants to accumulate significantly more chlorophyll when grown in low light conditions than in high light conditions suggests that carotenoid deficiency is at least partly responsible for premature cessation of chloroplast development. In addition to accumulation of low levels of chlorophyll and carotenoid pigments, pac mutants are abscisic acid (ABA) deficient and have characteristics which may be explained by this deficiency. These include reduced seed viability and, in enclosed growth conditions, increased leaf growth. Plants transformed with an antisense PAC construct often bear viviparous embryos which may be symptomatic of a deficiency in ABA. Since carotenoids are precursors of ABA, a role for PAC in carotenoid biosynthesis is further supported. The nuclear-encoded. chloroplast-localized PAC protein has been implicated in the maturation of plastid-encoded mRNAs. Thus, PAC may affect the abundance of one or more chloroplast proteins which function in the synthesis or stability of carotenoids. Using the PROLIFERA gene as a marker for cell division, it is shown that cell division profiles in the pac shoot apex are disrupted. pac leaves are relatively normal in size and shape despite the light intensity-induced variability of leaf cell defects, (C) 2000 Annals of Botany Company.

UR - http://www.scopus.com/inward/record.url?scp=0033764485&partnerID=8YFLogxK

U2 - 10.1006/anbo.2000.1263

DO - 10.1006/anbo.2000.1263

M3 - Article

VL - 86

SP - 953

EP - 962

JO - ANNALS OF BOTANY

JF - ANNALS OF BOTANY

IS - 5

ER -