SGRL can regulate chlorophyll metabolism and contributes to normal plant growth and development in Pisum sativum L.
Among a set of genes in pea (Pisum sativum L.) that were induced under drought-stress growth conditions, one encoded a protein with significant similarity to a regulator of chlorophyll catabolism, SGR. This gene, SGRL, is distinct from SGR in genomic location, encoded carboxy-terminal motif, and expression through plant and seed development. Divergence of the two encoded proteins is associated with a loss of similarity in intron/exon gene structure. Transient expression of SGRL in leaves of Nicotiana benthamiana promoted the degradation of chlorophyll, in a manner that was distinct from that shown by SGR. Removal of a predicted transmembrane domain from SGRL reduced its activity in transient expression assays, although variants with and without this domain reduced SGR-induced chlorophyll degradation, indicating that the effects of the two proteins are not additive. The combined data suggest that the function of SGRL during growth and development is in chlorophyll re-cycling, and its mode of action is distinct from that of SGR. Studies of pea sgrL mutants revealed that plants had significantly lower stature and yield, a likely consequence of reduced photosynthetic efficiencies in mutant compared with control plants under conditions of high light intensity.
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
Andrew
A
Bell
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
Carol
C
Moreau
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
Catherine
C
Chinoy
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
Rebecca
R
Spanner
INRA/CNRS - URGV, 2 rue Gaston Crémieux, 91057, Evry, France.
Marion
M
Dalmais
INRA, UMR 1347 Agroécologie, Dijon, France.
Christine
C
Le Signor
INRA/CNRS - URGV, 2 rue Gaston Crémieux, 91057, Evry, France.
Abdel
A
Bendahmane
School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
Markus
M
Klenell
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK. claire.domoney@jic.ac.uk.
Claire
C
Domoney
D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D018532:Pisum sativum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
D010940:Plant Proteins; D002734:Chlorophyll
Chlorophyll turnover; Pea; SGR; Staygreen; TILLING mutants; Transient expression