Molecular mechanism of seed dormancy release induced by fluridone compared with cod stratification in Notopterygium incisum

Abstract

BackgroundNotopterygium incisum is an important Chinese medicinal plant. Its mature seeds have underdeveloped embryos and are physiological dormant. We found the seeds with full developed embryos can germinate after treated by fluridone (FL), an inhibitor of abscisic acid (ABA). In order to understand the molecular mechanisms underlying seed dormancy release by FL, we compared the transcriptomic changes in dormancy release induced by two different methods, FL and cold stratification (CS) in N. incisum. We further analyzed the gene expression patterns involved in seed germination and dormancy using quantitative reverse-transcription PCR.ResultsRNA-sequence analysis revealed more dramatic changes in the transcriptomes of FL than those in CS, particularly for genes involved in the biosynthesis and regulation of gibberellins (GAs) and ABA. The down-regulation of ABA biosynthesis genes and the dramatic up-regulation of NiCYP707As, an ABA catabolic gene, contributed to the reduced ABA levels in FL. The increased GA3 levels in CS-treated seeds were due to the up-regulation of NiGA3OX. Both NiABI5 (a positive ABA regulator) and NiGAI (a negative regulator of GA) were down-regulated in FL and CS. The upregulation of strigolactones (SLs; the metabolites with the same precursor as ABA) biosynthesis and regulatory genes in both FL- and CS-treated seeds indicates that SLs contribute positively to seed dormancy release in N. incisum.ConclusionsOur results indicated that FL- and CS-seed dormancy release possibly depends on two totally different mechanisms: alleviation of the effects of ABA and potentiation of the effects of GA, respectively. However, NiABI5 and NiGAI probably function as common factors integrating the effects of ABA and GA on seed dormancy release.Electronic supplementary materialThe online version of this article (10.1186/s12870-018-1333-2) contains supplementary material, which is available to authorized users.

Comparative transcriptome analysis reveals the potential mechanism of GA3-induced dormancy release in Suaeda glauca black seeds

“…Morris et al (1989) found that there was no significant association between dormancy level and seed ABA content. In addition, GA biosynthesis genes, including SgGA3ox1 and SgKAO1, were significantly up-regulated during GA 3 -induced dormancy release in our study, while the GA catabolic gene, SgGA2ox8, was significantly down-regulated (Figure 4C), which was consistent with seed dormancy release induced by cold stratification in Notopterygium incisum (Li et al, 2018). These findings imply that exogenous GA 3 may enhance seed endogenous GA levels by enhancing expression of GA biosynthesis genes SgGA3ox1 and SgKAO1 and suppressing the catabolic gene SgGA2ox8, further promoting the germination rate of S. glauca black seeds (Figure 1B).…”

“…However, the qRT-PCR results showed that SgGA3ox1 (TRINITY_DN3218_c0_g1) was up-regulated in the "Pg_vs_B0" group but was down-regulated in the transcriptome analysis. The different expression patterns presented in the qRT-PCR result and RNA-seq data were also described for some candidate genes in other studies (Li et al, 2018). Similarly, the expression level of SgPER12 (TRINITY_DN569_c0_g1) was also different from that of RNA-Seq in the "Bg_vs_Pg" group (Figure 7).…”

Transcriptome profiles revealed molecular mechanisms of alternating temperatures in breaking the epicotyl morphophysiological dormancy of Polygonatum sibiricum seeds

“…It was also found that P. kingianum germinated seeds at corm stage had the higher ABA content than cold-stratified and non-dormant germinated seeds, which was consistent with the higher expression of ABA synthesis-related transcripts [ 33 ]. Fluridone is an inhibitor of ABA biosynthesis and promoted seed dormancy release like cold stratification [ 47 , 48 ]. In our recent pre-experiments, we observed that fluridone-treated P. sibiricum seeds germinate at a higher rate than untreated seeds (data not shown).…”

Molecular mechanisms and hormonal regulation underpinning morphological dormancy: a case study using Apium graveolens (Apiaceae)

“…Examples for this for Apiaceae include Pastinaca sativa and Conium maculatum, which, depending on the season or year, can produce mixtures of MD and MPD fruits Baskin, 1979, 1990); other examples are also shown (Figure 1, SI Methods, Data S1). For MPD fruits, additional pre-treatment to release the physiological dormancy block in phase I, thereby inducing embryo growth, usually takes several weeks of warm or cold stratification (Aihua et al, 2018;Baskin and Baskin, 2014;Cho et al, 2018;Porceddu et al, 2017;Zhang et al, 2019). In some of these species with MPD, the long stratification pre-treatment can be replaced by GA or fluridone (reducing ABA contents).…”