Early iron deficiency stress response in leaves of sugar beet.
Plant Physiol
; 108(4): 1487-94, 1995 Aug.
Article
en En
| MEDLINE
| ID: mdl-7659749
ABSTRACT
Iron nutrient deficiency was investigated in leaves of hydroponically grown sugar beets (Beta vulgaris) to determine how ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) gene expression is affected when thylakoid components of photosynthesis are diminished. Rubisco polypeptide content was reduced by 60% in severely iron-stressed leaves, and the reduction was directly correlated to chlorophyll content. The concentration of Rubisco protein in iron-stressed leaves was found to be regulated by availability of mRNAs, and CO2 fixation by Rubisco was reduced from 45 mumol CO2 m-2 s-1 in extracts from iron-sufficient leaves to 20 mumol CO2 m-2 s-1 in extracts from severely stressed leaves. The rate of CO2 fixation was directly correlated to leaf chlorophyll content. Rubisco in iron-sufficient control leaves was 59% activated, whereas in severely stressed leaves grown under the same light, Rubisco was 43% activated. RNA synthesis was reduced by about 50% in iron-deficient leaves, but 16S and 25S rRNA and ctDNA were essentially unaffected by iron stress.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Ribulosa-Bifosfato Carboxilasa
/
Hojas de la Planta
/
Regulación de la Expresión Génica de las Plantas
/
Deficiencias de Hierro
Idioma:
En
Revista:
Plant Physiol
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos