Auxin is an important phytohormone which mediates diverse development processes in plants. Published research has demonstrated that auxin induces seed dormancy. However, the precise mechanisms underlying the effect of auxin on seed germination need further investigation, especially the relationship between auxins and both abscisic acid (ABA) and gibberellins (GAs), the latter two phytohormones being the key regulators of seed germination. Here we report that exogenous auxin treatment represses soybean seed germination by enhancing ABA biosynthesis, while impairing GA biogenesis, and finally decreasing GA1/ABA and GA4/ABA ratios. Microscope observation showed that auxin treatment delayed rupture of the soybean seed coat and radicle protrusion. qPCR assay revealed that transcription of the genes involved in ABA biosynthetic pathway was up-regulated by application of auxin, while expression of genes involved in GA biosynthetic pathway was down-regulated. Accordingly, further phytohormone quantification shows that auxin significantly increased ABA content, whereas the active GA1 and GA4 levels were decreased, resulting insignificant decreases in the ratiosGA1/ABA and GA4/ABA.Consistent with this, ABA biosynthesis inhibitor fluridone reversed the delayed-germination phenotype associated with auxin treatment, while paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Altogether, exogenous auxin represses soybean seed germination by mediating ABA and GA biosynthesis.
Exogenous auxin represses soybean seed germination through decreasing the gibberellin/abscisic acid (GA/ABA) ratio
H. Shuai,Y. Meng,Xiaofeng Luo,F. Chen,Wenguan Zhou,Yujia Dai,Ying Qi,Junbo Du,Feng Yang,Jiang Liu,Wenyu Yang,K. Shu
Published 2017 in Scientific Reports
ABSTRACT
PUBLICATION RECORD
- Publication year
2017
- Venue
Scientific Reports
- Publication date
2017-10-03
- Fields of study
Biology, Medicine, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- aba biosynthetic pathway
The biochemical and transcriptional pathway in soybean seeds that produces abscisic acid.
Aliases: abscisic acid biosynthetic pathway
- abscisic acid (aba)
A plant hormone associated with seed dormancy and included as a quantified regulator in the germination assays.
Aliases: ABA, abscisic acid
- auxin
An important plant phytohormone used here as the exogenous treatment applied to soybean seeds.
- fluridone
An inhibitor of ABA biosynthesis used to test whether blocking ABA production alters germination under auxin treatment.
- ga1/aba ratio
The ratio between the active gibberellin GA1 and ABA used as a hormone-balance metric in soybean seeds.
Aliases: GA1 to ABA ratio
- ga4/aba ratio
The ratio between the active gibberellin GA4 and ABA used as a hormone-balance metric in soybean seeds.
Aliases: GA4 to ABA ratio
- ga biosynthetic pathway
The biochemical and transcriptional pathway in soybean seeds that produces gibberellins.
Aliases: gibberellin biosynthetic pathway
- gibberellin (ga)
A class of plant hormones that includes the bioactive forms GA1 and GA4 measured in the study.
Aliases: GA, gibberellins
- paclobutrazol
An inhibitor of GA biosynthesis used to test the role of gibberellin production in soybean seed germination.
- soybean seed germination
The seed germination process in soybean, including seed coat rupture and radicle protrusion.
Aliases: soybean germination
REFERENCES
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