Embryo transcriptome and miRNA analyses reveal the regulatory network of seed dormancy in Ginkgo biloba

Abstract

Seed dormancy is crucial for plant survival and prevents seed germination out of season. However, little is known about the regulatory mechanism of morphophysiological seed dormancy. Ginkgo biloba L. is one of the most ancient gymnosperms, and the completion of seed germination in this species requires cold and moist stratification. Here, we observed that at the mature seed stage, the embryo was not fully developed in G. biloba seeds. During dormancy stages, the length and weight of the embryo significantly increased, and nutrients accumulated in cotyledons. We further found that abscisic acid (ABA), gibberellic acid (GA), cytokinin and ethylene were integrated in the seed dormancy induction, maintenance and release processes, and GA biosynthesis and signaling transduction specifically act on dormancy release. Combining mRNA and miRNA analyses, we demonstrated that miRNA156 is involved in the regulation of morphophysiological dormancy. Our analyses revealed that G. biloba seed dormancy belongs to the ancestral morphophysiological dormancy type, which is not only regulated by the balance of ABA/GA, but also by other hormones associated with embryo morphological development, as well as genes related to embryo differentiation and development. These findings helped with elucidating the comprehensive regulatory network of morphophysiological dormancy in tree seeds.

Transcriptome and Metabolite Conjoint Analysis Reveals the Seed Dormancy Release Process in Callery Pear

“…In addition, the absolute ABA content was much higher than the absolute GA3 content and the ABA/GA3 ratio showed a similar trend to ABA content (Figure 1B-E). These findings are consistent with those in the seeds of red bayberry [29], celery [30], and ginkgo [31]. Simultaneously, the expression patterns of several ABA and GA biosynthesis and deactivation genes, including SDRs, CYP707As, KO, KAO, and GA20oxs, exhibited high correlations with the changes in ABA and GA3 levels (Figure 4A).…”

Levels and Expression Patterns of Endogenous Hormones during Seed Germination of Dongxiang Wild Rice

“…Dynamic variations of the ABA/GA ratio during germination showed that DXWR had a similar ratio with 9311 during 24 h imbibition, but significantly higher ratio than 9311 during 24 h-48 h imbibition (Fig. 2), consistent with previous studies showed that a high ABA/GA ratio is critical for the induction of maturation and germination suppression in early seed development programming [25]. In our results, the ABA/IAA ratio for DXWR only slightly fluctuated, but one ratio slack at 36 h and two ratio peaks at early and late stages of seed germination for 9311 were observed (Fig.…”

“…Xiao et al found that the content of IAA in the embryo gradually increased during seed germination, and then reach a maximum at 12 h, but then decreased at 48h [24]. Jia et al found that GA biosynthesis and signaling transduction specifically act on seed dormancy release [25]. Several physiological and genetic analyses have demonstrated the requirement of GA for germination; GA can promote seed germination through enhancing the growth potential of the embryo and overcoming the mechanical barriers imposed by covering layers surrounding embryo [4,12].…”

Physiological and Genetic Analysis of Leaves from the Resprouters of an Old Ginkgo biloba Tree

“…Ginkgo biloba L., a fascinating and economically important gymnosperm, is the only living representative of the order Ginkgoales, which probably originated circa 280 million years ago [12]. It exhibits some unique features related to its sexual reproduction process, phylogenetic position, and evolutionary history [13][14][15]. At present, G. biloba has a wide Forests 2021, 12, 1255 2 of 16 distribution across different elevations and latitudes and generally has a long lifespan.…”