title: Proanthocyanidins inhibit seed germination by maintaining a high level of abscisic acid in Arabidopsis thaliana.
abstract: Proanthocyanidins (PAs) are the main products of the flavonoid biosynthetic pathway in seeds, but their biological function during seed germination is still unclear. We observed that seed germination is delayed with the increase of exogenous PA concentration in Arabidopsis. A similar inhibitory effect occurred in peeled Brassica napus seeds, which was observed by measuring radicle elongation. Using abscisic acid (ABA), a biosynthetic and metabolic inhibitor, and gene expression analysis by real-time polymerase chain reaction, we found that the inhibitory effect of PAs on seed germination is due to their promotion of ABA via de novo biogenesis, rather than by any inhibition of its degradation. Consistent with the relationship between PA content and ABA accumulation in seeds, PA-deficient mutants maintain a lower level of ABA compared with wild-types during germination. Our data suggest that PA distribution in the seed coat can act as a doorkeeper to seed germination. PA regulation of seed germination is mediated by the ABA signaling pathway.
authors: Department of Biology, Hong Kong Baptist University, Hong Kong, China.
authors: Liguo
authors: L
authors: Jia
authors: Qiuyu
authors: Q
authors: Wu
authors: Nenghui
authors: N
authors: Ye
authors: Rui
authors: R
authors: Liu
authors: Lu
authors: L
authors: Shi
authors: Weifeng
authors: W
authors: Xu
authors: Hui
authors: H
authors: Zhi
authors: A N M Rubaiyath Bin
authors: AN
authors: Rahman
authors: Yiji
authors: Y
authors: Xia
authors: Jianhua
authors: J
authors: Zhang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029688:Brassica napus / Q000187:drug effects / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects*; D009154:Mutation / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D044945:Proanthocyanidins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
chemical_list: D044945:Proanthocyanidins; D012333:RNA, Messenger; D000040:Abscisic Acid