Melatonin Priming Promotes Crop Seed Germination and Seedling Establishment Under Flooding Stress by Mediating ABA, GA, and ROS Cascades.

Both seed germination and subsequent seedling establishment are key checkpoints during the life cycle of seed plants, yet flooding stress markedly inhibits both processes, leading to economic losses from agricultural production. Here, we report that melatonin (MT) seed priming treatment enhances the performance of seeds from several crops, including soybean, wheat, maize, and alfalfa, under flooding stress. Transcriptome analysis revealed that MT priming promotes seed germination and seedling establishment associated with changes in abscisic acid (ABA), gibberellin (GA), and reactive oxygen species (ROS) biosynthesis and signaling pathways.

Illuminating the Arabidopsis circadian epigenome: Dynamics of histone acetylation and deacetylation.

The circadian clock generates rhythms in biological processes including plant development and metabolism. Light synchronizes the circadian clock with the day and night cycle and also triggers developmental transitions such as germination, or flowering. The circadian and light signaling pathways are closely interconnected and understanding their mechanisms of action and regulation requires the integration of both pathways in their complexity.

Multifaceted Signaling Networks Mediated by Abscisic Acid Insensitive 4.

Although ABSCISIC ACID INSENSITIVE 4 (ABI4) was initially demonstrated as a key positive regulator in the phytohormone abscisic acid (ABA) signaling cascade, multiple studies have now shown that it is actually involved in the regulation of several other cascades, including diverse phytohormone biogenesis and signaling pathways, various developmental processes (such as seed dormancy and germination, seedling establishment, and root development), disease resistance and lipid metabolism. Consistent with its versatile biological functions, ABI4 either activates or represses transcription of its target genes. The upstream regulators of ABI4 at both the transcription and post-transcription levels have also been documented in recent years.

Gibberellins and auxin regulate soybean hypocotyl elongation under low light and high-temperature interaction.

Soybean is an important oilseed crop grown globally. However, two examples of environmental stresses that drastically regulate soybean growth are low light and high-temperature. Emerging evidence suggests a possible interconnection between these two environmental stimuli.

Plant waterlogging/flooding stress responses: From seed germination to maturation.

Global climate change is strongly associated with variations in precipitation and flooding events. Flooding usually causes submergence- or partial submergence stress in plants, which significantly has a negative influence on agricultural production, from seed germination to vegetative and reproductive growth. Flooding stress results in crop growth under low oxygen conditions and thus, negatively affects the developmental periods of plant lifecycle.

Shading of the mother plant during seed development promotes subsequent seed germination in soybean.

The effect of shading during seed development on subsequent germination remains largely unknown. In this study, two soybean (Glycine max) seed production systems, monocropping (MC) and maize-soybean intercropping (IC), were employed to examine the effects of shading of the mother plant on subsequent seed germination. Compared to the MC soybean seeds, which received light, the developing IC seeds were exposed to shade resulting from the taller neighboring maize plants.

A matter of life and death: Molecular, physiological, and environmental regulation of seed longevity.

Both seed germination and early seedling establishment are important biological processes in a plant's lifecycle. Seed longevity is a key trait in agriculture, which directly influences seed germination and ultimately determines crop productivity and hence food security. Numerous studies have demonstrated that seed deterioration is regulated by complex interactions between diverse endogenous genetically controlled factors and exogenous environmental cues, including temperature, relative humidity, and oxygen partial pressure during seed storage.

Genome-wide identification of GRF transcription factors in soybean and expression analysis of GmGRF family under shade stress.

Background: The Growth-regulating factor (GRF) family encodes plant-specific transcription factors which contain two conserved domains, QLQ and WRC. Members of this family play vital roles in plant development and stress response processes. Although GRFs have been identified in various plant species, we still know little about the GRF family in soybean (Glycine max).

ABI4 regulates the floral transition independently of ABI5 and ABI3.

Emerging evidence suggests that the stress hormone abscisic acid (ABA) is also involved in the floral transition control. The transcription factors ABA INSENSITIVE4 (ABI4) and ABI5 negatively regulate flowering by directly promoting FLOWERING LOCUS C expression, and ABI3 also negatively regulates the floral transition. However, the genetic relationships between ABI4 and both ABI5 and ABI3 remain elusive.

DA-6 promotes germination and seedling establishment from aged soybean seeds by mediating fatty acid metabolism and glycometabolism.

Soybean seeds contain higher concentrations of oil (triacylglycerol) and fatty acids than do cereal crop seeds, and the oxidation of these biomolecules during seed storage significantly shortens seed longevity and decreases germination ability. Here, we report that diethyl aminoethyl hexanoate (DA-6), a plant growth regulator, increases germination and seedling establishment from aged soybean seeds by increasing fatty acid metabolism and glycometabolism. Phenotypic analysis showed that DA-6 treatment markedly promoted germination and seedling establishment from naturally and artificially aged soybean seeds.

Abscisic Acid and Gibberellins Antagonistically Mediate Plant Development and Abiotic Stress Responses.

Phytohormones regulate numerous important biological processes in plant development and biotic/abiotic stress response cascades. More than 50 and 100 years have passed since the initial discoveries of the phytohormones abscisic acid (ABA) and gibberellins (GA), respectively. Over the past several decades, numerous elegant studies have demonstrated that ABA and GA antagonistically regulate many plant developmental processes, including seed maturation, seed dormancy and germination, root initiation, hypocotyl and stem elongation, and floral transition.

APETALA 2-domain-containing transcription factors: focusing on abscisic acid and gibberellins antagonism.

The phytohormones abscisic acid (ABA) and gibberellin (GA) antagonistically mediate diverse plant developmental processes including seed dormancy and germination, root development, and flowering time control, and thus the optimal balance between ABA and GA is essential for plant growth and development. Although more than a half and one century have passed since the initial discoveries of ABA and GA, respectively, the precise mechanisms underlying ABA-GA antagonism still need further investigation. Emerging evidence indicates that two APETALA 2 (AP2)-domain-containing transcription factors (ATFs), ABI4 in Arabidopsis and OsAP2-39 in rice, play key roles in ABA and GA antagonism.

Exogenous auxin represses soybean seed germination through decreasing the gibberellin/abscisic acid (GA/ABA) ratio.

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.

Karrikins: Regulators Involved in Phytohormone Signaling Networks during Seed Germination and Seedling Development.

Seed germination and early seedling establishment are critical stages during a plant's life cycle. These stages are precisely regulated by multiple internal factors, including phytohormones and environmental cues such as light. As a family of small molecules discovered in wildfire smoke, karrikins (KARs) play a key role in various biological processes, including seed dormancy release, germination regulation, and seedling establishment.