Proteomic analysis of common bean seed with storage protein deficiency reveals up-regulation of sulfur-rich proteins and starch and raffinose metabolic enzymes, and down-regulation of the secretory pathway.
A deficiency in major seed storage proteins is associated with a nearly two-fold increase in sulfur amino acid content in genetically related lines of common bean (Phaseolus vulgaris). Their mature seed proteome was compared by an approach combining label-free quantification by spectral counting, 2-DE, and analysis of selective extracts. Lack of phaseolin, phytohemagglutinin and arcelin was mainly compensated by increases in legumin, alpha-amylase inhibitors and mannose lectin FRIL. Along with legumin, albumin-2, defensin and albumin-1 were major contributors to the elevated sulfur amino acid content. Coordinate induction of granule-bound starch synthase I, starch synthase II-2 and starch branching enzyme were associated with minor alteration of starch composition, whereas increased levels of UDP-glucose 4-epimerase were correlated with a 30% increase in raffinose content. Induction of cell division cycle protein 48 and ubiquitin suggested enhanced ER-associated degradation. This was not associated with a classical unfolded protein response as the levels of ER HSC70-cognate binding protein were actually reduced in the mutant. Repression of rab1 GTPase was consistent with decreased traffic through the secretory pathway. Collectively, these results have implications for the nutritional quality of common bean, and provide information on the pleiotropic phenotype associated with storage protein deficiency in a dicotyledonous seed.
Marsolais
Frédéric
F
Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, ON, Canada. Frederic.Marsolais@agr.gc.ca
Pajak
Agnieszka
A
Yin
Fuqiang
F
Taylor
Meghan
M
Gabriel
Michelle
M
Merino
Diana M
DM
Ma
Vanessa
V
Kameka
Alexander
A
Vijayan
Perumal
P
Pham
Hai
H
Huang
Shangzhi
S
Rivoal
Jean
J
Bett
Kirstin
K
Hernández-Sebastià
Cinta
C
Liu
Qiang
Q
Bertrand
Annick
A
Chapman
Ralph
R
D015061:1,4-alpha-Glucan Branching Enzyme / Q000235:genetics; D000603:Amino Acids, Sulfur / Q000378:metabolism; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D027805:Phaseolus / Q000201:enzymology / Q000235:genetics*; D010940:Plant Proteins; D040901:Proteomics / Q000379:methods; D011887:Raffinose / Q000378:metabolism; D055314:Seed Storage Proteins / Q000235:genetics*; D013214:Starch Synthase / Q000235:genetics; D014534:UDPglucose 4-Epimerase / Q000235:genetics; D015854:Up-Regulation; D020761:rab1 GTP-Binding Proteins / Q000235:genetics
D000603:Amino Acids, Sulfur; D010940:Plant Proteins; D055314:Seed Storage Proteins; C434607:granule-bound starch synthase I; C111377:starch synthase II; D015061:1,4-alpha-Glucan Branching Enzyme; D013214:Starch Synthase; D020761:rab1 GTP-Binding Proteins; D014534:UDPglucose 4-Epimerase; D011887:Raffinose