CDPK6 phosphorylates and stabilizes MYB30 to promote hyperoside biosynthesis that prolongs the duration of full-blooming in okra

Transcriptome and metabolome analyses reveal the regulatory role of MdPYL9 in drought resistance in apple

BACKGROUND

The mechanisms by which the apple MdPYL9 gene mediates the response to drought stress remain unclear. Here, transcriptome and metabolome analyses of apple plants under drought were used to investigate the mechanisms by which MdPYL9 regulates the response to drought stress in apple. MdPYL9-overexpressed transgenic and non-transgenic apple histoculture seedlings were rooted, transplanted, and subjected to drought treatments to clarify the mechanisms underlying the responses of apples to drought stress through phenotypic observations, physiological and biochemical index measurements, and transcriptomic and metabolomic analyses.

RESULTS

Under drought stress treatment, transgenic plants were less affected by drought stress than non-transgenic plants. Decreases in the net photosynthetic rate, stomatal conductance, and transpiration rate of transgenic apple plants were less pronounced in transgenic plants than in non-transgenic plants, and increases in the intercellular CO2 concentration were less pronounced in transgenic plants than in non-transgenic plants. The relative electrical conductivity and content of malondialdehyde, superoxide anion, and hydrogen peroxide were significantly lower in transgenic plants than in non-transgenic plants, and the chlorophyll content and activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) were significantly higher in transgenic plants than in non-transgenic plants. The number of differentially expressed genes (DEGs) involved in the response to drought stress was lower in transgenic plants than in non-transgenic plants, and the most significant and highly annotated DEGs in the transgenic plants were involved in the flavonoid biosynthesis pathway, and the most significant and highly annotated DEGs in control plants were involved in the phytohormone signal transduction pathway. The number of differentially accumulated metabolites involved in the response to drought stress was lower in transgenic plants than in non-transgenic plants, and up-regulated metabolites were significantly enriched in apigenin-7-O-glucoside in transgenic plants and in abscisic acid in non-transgenic plants. In the flavonoid biosynthetic pathway, the expression of genes encoding chalcone synthase (CHS) and chalcone isomerase (CHI) was more significantly down-regulated in non-transgenic plants than in transgenic plants, and the expression of the gene encoding 4-coumarate-CoA ligase (4CL) was more significantly up-regulated in transgenic plants than in non-transgenic plants, which resulted in the significant up-regulation of apigenin-7-O-glucoside in transgenic plants.

CONCLUSIONS

The above results indicated that the over-expression of MdPYL9 increased the drought resistance of plants under drought stress by attenuating the down-regulation of the expression of genes encoding CHS and CHI and enhancing the up-regulated expression of the gene encoding 4CL, which enhanced the content of apigenin-7-O-glucoside.

CcNFYB3-CcMATE35 and LncRNA CcLTCS-CcCS modules jointly regulate the efflux and synthesis of citrate to enhance aluminium tolerance in pigeon pea

Aluminium (Al) toxicity decreases crop production in acid soils in general, but many crops have evolved complex mechanisms to resist it. However, our current understanding of how plants cope with Al stress and perform Al resistance is still at the initial stage. In this study, the citrate transporter CcMATE35 was identified to be involved in Al stress response. The release of citrate was increased substantially in CcMATE35 over-expression (OE) lines under Al stress, indicating enhanced Al resistance. It was demonstrated that transcription factor CcNFYB3 regulated the expression of CcMATE35, promoting the release of citrate from roots to increase Al resistance in pigeon pea. We also found that a Long noncoding RNA Targeting Citrate Synthase (CcLTCS) is involved in Al resistance in pigeon pea. Compared with controls, overexpression of CcLTCS elevated the expression level of the Citrate Synthase gene (CcCS), leading to increases in root citrate level and citrate release, which forms another module to regulate Al resistance in pigeon pea. Simultaneous overexpression of CcNFYB3 and CcLTCS further increased Al resistance. Taken together, these findings suggest that the two modules, CcNFYB3-CcMATE35 and CcLTCS-CcCS, jointly regulate the efflux and synthesis of citrate and may play an important role in enhancing the resistance of pigeon pea under Al stress.

Flavonols affect the interrelated glucosinolate and camalexin biosynthetic pathways in Arabidopsis thaliana

Flavonols are structurally and functionally diverse biomolecules involved in plant biotic and abiotic stress tolerance, pollen development, and inhibition of auxin transport. However, their effects on global gene expression and signaling pathways are unclear. To explore the roles of flavonol metabolites in signaling, we performed comparative transcriptome and targeted metabolite profiling of seedlings from the flavonol-deficient Arabidopsis loss-of-function mutant flavonol synthase1 (fls1) with and without exogenous supplementation of flavonol derivatives (kaempferol, quercetin, and rutin). RNA-seq results indicated that flavonols modulate various biological and metabolic pathways, with significant alterations in camalexin and aliphatic glucosinolate synthesis. Flavonols negatively regulated camalexin biosynthesis but appeared to promote the accumulation of aliphatic glucosinolates via transcription factor-mediated up-regulation of biosynthesis genes. Interestingly, upstream amino acid biosynthesis genes involved in methionine and tryptophan synthesis were altered under flavonol deficiency and exogenous supplementation. Quercetin treatment significantly up-regulated aliphatic glucosinolate biosynthesis genes compared with kaempferol and rutin. In addition, expression and metabolite analysis of the transparent testa7 mutant, which lacks hydroxylated flavonol derivatives, clarified the role of quercetin in the glucosinolate biosynthesis pathway. This study elucidates the molecular mechanisms by which flavonols interfere with signaling pathways, their molecular targets, and the multiple biological activities of flavonols in plants.

The parallel biosynthesis routes of hyperoside from naringenin in Hypericum monogynum

Hyperoside is a bioactive flavonoid galactoside in both medicinal and edible plants. It plays an important physiological role in the growth of flower buds. However, the hyperoside biosynthesis pathway has not been systematically elucidated in plants, including its original source, Hypericaceae. Our group found abundant hyperoside in the flower buds of Hypericum monogynum, and we sequenced its transcriptome to study the biosynthetic mechanism of hyperoside. After gene screening and functional verification, four kinds of key enzymes were identified. Specifically, HmF3Hs (flavanone 3-hydroxylases) and HmFLSs (flavonol synthases) could catalyze flavanones into dihydroflavonols, as well as catalyzing dihydroflavonols into flavonols. HmFLSs could also convert flavanones into flavonols and flavones with varying efficiencies. HmF3'H (flavonoid 3'-hydroxylase) was found to act broadly on 4'-hydroxyl flavonoids to produce 3',4'-diydroxylated flavanones, dihydroflavonols, flavonols, and flavones. HmGAT (flavonoid 3-O-galactosyltransferase) would transform flavonols into the corresponding 3-O-galactosides, including hyperoside. The parallel hyperoside biosynthesis routes were thus depicted, one of which was successfully reconstructed in Escherichia coli BL21(DE3) by feeding naringenin, resulting in a hyperoside yield of 25 mg/l. Overall, this research not only helped us understand the interior catalytic mechanism of hyperoside in H. monogynum concerning flower development and bioactivity, but also provided valuable insights into these enzyme families.

Sorbitol induces flower bud formation via the MADS-box transcription factor EjCAL in loquat

Sorbitol is an important signaling molecule in fruit trees. Here, we observed that sorbitol increased during flower bud differentiation (FBD) in loquat (Eriobotrya japonica Lindl.). Transcriptomic analysis suggested that bud formation was associated with the expression of the MADS-box transcription factor (TF) family gene, EjCAL. RNA fluorescence in situ hybridization showed that EjCAL was enriched in flower primordia but hardly detected in the shoot apical meristem. Heterologous expression of EjCAL in Nicotiana benthamiana plants resulted in early FBD. Yeast-one-hybrid analysis identified the ERF12 TF as a binding partner of the EjCAL promoter. Chromatin immunoprecipitation-PCR confirmed that EjERF12 binds to the EjCAL promoter, and β-glucuronidase activity assays indicated that EjERF12 regulates EjCAL expression. Spraying loquat trees with sorbitol promoted flower bud formation and was associated with increased expression of EjERF12 and EjCAL. Furthermore, we identified EjUF3GaT1 as a target gene of EjCAL and its expression was activated by EjCAL. Function characterization via overexpression and RNAi reveals that EjUF3GaT1 is a biosynthetic gene of flavonoid hyperoside. The concentration of the flavonoid hyperoside mirrored that of sorbitol during FBD and exogenous hyperoside treatment also promoted loquat bud formation. We identified a mechanism whereby EjCAL might regulate hyperoside biosynthesis and confirmed the involvement of EjCAL in flower bud formation in planta. Together, these results provide insight into bud formation in loquat and may be used in efforts to increase yield.

The Effect of Stress Hormones, Ultraviolet C, and Stilbene Precursors on Expression of Calcineurin B-like Protein (CBL) and CBL-Interacting Protein Kinase (CIPK) Genes in Cell Cultures and Leaves of Vitis amurensis Rupr

Calcium serves as a crucial messenger in plant stress adaptation and developmental processes. Plants encode several multigene families of calcium sensor proteins with diverse functions in plant growth and stress responses. Several studies indicated that some calcium sensors may be involved in the regulation of secondary metabolite production in plant cells. The present study aimed to investigate expression of calcineurin B-like proteins (CBL) and CBL-interacting protein kinase (CIPK) in response to conditions inducting biosynthesis of stilbenes in grapevine. We investigated CBL and CIPK gene expression in wild-growing grapevine Vitis amurensis Rupr., known as a rich stilbene source, in response to the application of stilbene biosynthesis-inducing conditions, including application of stress hormones (salicylic acid or SA, methyl jasmonate or MeJA), phenolic precursors (p-coumaric acids or CA), and ultraviolet irradiation (UV-C). The influence of these effectors on the levels of 13 VaCBL and 27 VaCIPK mRNA transcripts as well as on stilbene production was analyzed by quantitative real-time RT-PCR in the leaves and cell cultures of V. amurensis. The data revealed that VaCBL4-1 expression considerably increased after UV-C treatment in both grapevine cell cultures and leaves. The expression of VaCIPK31, 41-1, and 41-2 also increased, but this increase was mostly detected in cell cultures of V. amurensis. At the same time, expression of most VaCBL and VaCIPK genes was markedly down-regulated both in leaves and cell cultures of V. amurensis, which may indicate that the CBLs and CIPKs are involved in negative regulation of stilbene accumulation (VaCBL8, 10a-2, 10a-4, 11, 12, VaCIPK3, 9-1, 9-2, 12, 21-1, 21-2, 33, 34, 35, 36, 37, 39, 40, 41-3, 41-4). The results obtained provide new information of CBL and CIPK implication in the regulation of plant secondary metabolism in response to stress hormones, metabolite precursors, and UV-C irradiation.

Transcriptome analysis reveals the crucial function of hyperoside in inhibiting anthocyanin accumulation in grape (Vitis vinifera L.) fruits by inducing VvMYB62

INTRODUCTION

The formation of color in plants is significantly dependent on anthocyaninpigments. Grape species vary in color due to the differences in anthocyanin accumulation. It is widely recognized that both biotic and abiotic conditions may have an impact on anthocyanin synthesis in plants. The underlying molecular mechanisms by which external application of hyperoside impacts anthocyanin formation in grapes, however, have received little attention.

METHODS

In the current study,the transcriptome of Gemstone seedless grape was examined using high-throughput RNA sequencing at various developmental stages reply to both control and hyperoside treatments.

RESULTS

The results of this study suggested that the major genes controlling anthocyanin accumulation in response to the externalinjection of hyperoside could be VvMYB62, VvPAL, VvCHS, and VvF3'5'H.Quantitative reverse transcription PCR (RT-qPCR) results were used to confirm the changes in the expression levels of the genes encoding the anthocyanin biosynthesis pathway under the control and hyperoside treatments. Using a transient transformation system, it was discovered that VvMYB62 was shown to regulate the anthocyanin accumulation at both the transcriptional and posttranslational levels and could be influenced by the external administration of hyperoside. In grape embryogenic calli, hyperoside could specifically suppress theexpression of VvMYB62 and anthocyanin accumulation. In this instance, the VvMYB62 characterisation brought attention to the significance of exogenous hyperoside-induced anthocyanin accumulation. Therefore, the results demonstrated that VvMYB62 could be hindered in the process of grape during anthocyanin accumulation caused by hyperoside.

DISCUSSION

These findings offer excellent candidate genes in the future breeding of novel grape varieties in addition to serving as a crucial reference for understanding the underlying molecular processes of hyperoside suppression of anthocyanin formation in plants.

Molecular mechanism of naringenin regulation on flavonoid biosynthesis to improve the salt tolerance in pigeon pea (Cajanus cajan (Linn.) Millsp.)

Flavonoids are important secondary metabolites in the plant growth and development process. As a medicinal plant, pigeon pea is rich in secondary metabolites. As a flavonoid, there are few studies on the regulation mechanism of naringenin in plant stress resistance. In our study, we found that naringenin can increase the pigeon pea's ability to tolerate salt and influence the changes that occur in flavonoids including naringenin, genistein and biochanin A. We analyzed the transcriptome data after 1 mM naringenin treatment, and identified a total of 13083 differentially expressed genes. By analyzing the metabolic pathways of these differentially expressed genes, we found that these differentially expressed genes were enriched in the metabolic pathways of phenylpropanoid biosynthesis, starch and sucrose metabolism and so on. We focused on the analysis of flavonoid biosynthesis related pathways. Among them, the expression levels of enzyme genes CcIFS, CcCHI and CcCHS in the flavonoid biosynthesis pathway had considerably higher expression levels. By counting the number of transcription factors and the binding sites on the promoter of the enzyme gene, we screened the transcription factors CcMYB62 and CcbHLH35 related to flavonoid metabolism. Among them, CcMYB62 has a higher expression level than the others. The hairy root transgene showed that CcMYB62 could induce the upregulation of CcCHI, and promote the accumulation of naringenin, genistein and biochanin A. Our study revealed the molecular mechanism of naringenin regulating flavonoid biosynthesis under salt stress in pigeon pea, and provided an idea for the role of flavonoids in plant resistance to abiotic stresses.

Identification of CDPKs involved in TaNOX7 mediated ROS production in wheat

As the critical sensors and decoders of calcium signal, calcium-dependent protein kinase (CDPK) has become the focus of current research, especially in plants. However, few resources are available on the properties and functions of CDPK gene family in Triticum aestivum (TaCDPK). Here, a total of 79 CDPK genes were identified in the wheat genome. These TaCDPKs could be classified into four subgroups on phylogenesis, while they may be classified into two subgroups based on their tissue and organ-spatiotemporal expression profiles or three subgroups according to their induced expression patterns. The analysis on the signal network relationships and interactions of TaCDPKs and NADPH (reduced nicotinamide adenine dinucleotide phosphate oxidases, NOXs), the key producers for reactive oxygen species (ROS), showed that there are complicated cross-talks between these two family proteins. Further experiments demonstrate that, two members of TaCDPKs, TaCDPK2/4, can interact with TaNOX7, an important member of wheat NOXs, and enhanced the TaNOX7-mediated ROS production. All the results suggest that TaCDPKs are highly expressed in wheat with distinct tissue or organ-specificity and stress-inducible diversity, and play vital roles in plant development and response to biotic and abiotic stresses by directly interacting with TaNOXs for ROS production.

Tree Peony R2R3-MYB Transcription Factor PsMYB30 Promotes Petal Blotch Formation by Activating the Transcription of the Anthocyanin Synthase Gene

Petal blotches are commonly observed in many angiosperm families and not only influence plant-pollinator interactions but also confer high ornamental value. Tree peony (Paeonia suffruticosa Andr.) is an important cut flower worldwide, but few studies have focused on its blotch formation. In this study, anthocyanins were found to be the pigment basis for blotch formation of P. suffruticosa, and peonidin-3,5-di-O-glucoside (Pn3G5G) was the most important component of anthocyanins, while the dihydroflavonol-4-reductase gene was the key factor contributing to blotch formation. Then, the R2R3-myeloblastosis (MYB) transcription factor PsMYB30 belonging to subgroup 1 was proven as a positive anthocyanin regulator with transcriptional activation and nuclear expression. Furthermore, silencing PsMYB30 in P. suffruticosa petals reduced blotch size by 37.9%, faded blotch color and decreased anthocyanin and Pn3G5G content by 23.6% and 32.9%, respectively. Overexpressing PsMYB30 increased anthocyanin content by 14.5-fold in tobacco petals. In addition, yeast one-hybrid assays, dual-luciferase assays and electrophoretic mobility shift assays confirmed that PsMYB30 could bind to the promoter of the anthocyanin synthase (ANS) gene and enhance its expression. Altogether, a novel MYB transcription factor, PsMYB30, was identified to promote petal blotch formation by activating the expression of PsANS involved in anthocyanin biosynthesis, which provide new insights for petal blotch formation in plants.

Systematic screening and validation of reliable reference genes for qRT-PCR analysis in Okra (Abelmoschus esculentus L.)

Quantitative real-time polymerase chain reaction (qRT-PCR) is a sensitive and widely used technique for quantifying gene expression levels, and its accuracy depends on the reference genes used for data normalization. To date, no reference gene has been reported in the nutritious and functional vegetable okra (Abelmoschus esculentus L.). Herein, 11 candidates of reference genes were selected and evaluated for their expression stability in okra in different tissues at different developmental stages by using three software algorithms (geNorm, NormFinder, BestKeeper) and a web-based tool (RefFinder). Among them, eukaryotic initiation factor 4 alpha (eIF4A) and protein phosphatase 2A (PP2A) showed the highest stability, while TUA5 had the lowest stability. The combined usage of these two most stable reference genes was sufficient to normalize gene expression in okra. Then, the above results were further validated by normalizing the expression of the cellulose synthase gene CesA4. This work provides appropriate reference genes for transcript normalization in okra, which will facilitate subsequent functional gene research on this vegetable crop.

MaMYB4 is a negative regulator and a substrate of RING-type E3 ligases MaBRG2/3 in controlling banana fruit ripening

Fruit ripening is a complex developmental process, which is modulated by both transcriptional and post-translational events. Control of fruit ripening is important in maintaining moderate quality traits and minimizing postharvest deterioration. In this study, we discovered that the transcription factor MaMYB4 acts as a negative regulator of fruit ripening in banana. The protein levels of MaMYB4 decreased gradually with banana fruit ripening, paralleling ethylene production, and decline in firmness. DNA affinity purification sequencing combined with RNA-sequencing analyses showed that MaMYB4 preferentially binds to the promoters of various ripening-associated genes including ethylene biosynthetic and cell wall modifying genes. Furthermore, ectopic expression of MaMYB4 in tomato delayed tomato fruit ripening, which was accompanied by downregulation of ethylene biosynthetic and cell wall modifying genes. Importantly, two RING finger E3 ligases MaBRG2/3, whose protein accumulation increased progressively with fruit ripening, were found to interact with and ubiquitinate MaMYB4, contributing to decreased accumulation of MaMYB4 during fruit ripening. Transient overexpression of MaMYB4 and MaBRG2/3 in banana fruit ripening delayed or promoted fruit ripening by inhibiting or stimulating ethylene biosynthesis, respectively. Taken together, we demonstrate that MaMYB4 negatively modulates banana fruit ripening, and that MaMYB4 abundance could be regulated by protein ubiquitination, thus providing insights into the role of MaMYB4 in controlling fruit ripening at both transcriptional and post-translational levels.

Molecular components associated with the regulation of flavonoid biosynthesis

Flavonoids exhibit amazing structural diversity and play different roles in plants. Besides, these compounds have been associated with several health benefits in humans. Several exogenous and endogenous cues, for example, light, temperature, nutrient status, and phytohormones have been reported as modulators of biosynthesis and accumulation of flavonoids. Thus, multiple hormones and stress-related signaling pathways are involved in the regulation of gene expression associated with this pathway. The transcriptional regulators belonging to the MYB and bHLH family transcription factors are well documented as the direct regulators of the structural genes associated with flavonoid biosynthesis. Recent studies also suggest that some of these factors are regulated by molecular components involved in stress and hormone signaling pathways. Adapter proteins for transcriptional activation or repression via recruitment of co-activators and co-repressors, respectively, E2 ubiquitin ligases, miRNA processing complex, and DNA methylation/demethylation factors have been recently discovered in various plants to play key roles in fine-tuning flavonoids synthesis. In the present review, we aim to provide comprehensive information about the role of different factors in the regulation of flavonoid biosynthesis. Besides, we describe the potential upstream regulators involved in the regulation of flavonoid biosynthesis within the context of available information. To sum up, the present review furnishes an updated account of signal transduction pathways modulating the biosynthesis of flavonoids.

Hyperoside promotes pollen tube growth by regulating the depolymerization effect of actin-depolymerizing factor 1 on microfilaments in okra

Mature pollen germinates rapidly on the stigma, extending its pollen tube to deliver sperm cells to the ovule for fertilization. The success of this process is an important factor that limits output. The flavonoid content increased significantly during pollen germination and pollen tube growth, which suggests it may play an important role in these processes. However, the specific mechanism of this involvement has been little researched. Our previous research found that hyperoside can prolong the flowering period of Abelmoschus esculentus (okra), but its specific mechanism is still unclear. Therefore, in this study, we focused on the effect of hyperoside in regulating the actin-depolymerizing factor (ADF), which further affects the germination and growth of pollen. We found that hyperoside can prolong the effective pollination period of okra by 2-3-fold and promote the growth of pollen tubes in the style. Then, we used Nicotiana benthamiana cells as a research system and found that hyperoside accelerates the depolymerization of intercellular microfilaments. Hyperoside can promote pollen germination and pollen tube elongation in vitro. Moreover, AeADF1 was identified out of all AeADF genes as being highly expressed in pollen tubes in response to hyperoside. In addition, hyperoside promoted AeADF1-mediated microfilament dissipation according to microfilament severing experiments in vitro. In the pollen tube, the gene expression of AeADF1 was reduced to 1/5 by oligonucleotide transfection. The decrease in the expression level of AeADF1 partially reduced the promoting effect of hyperoside on pollen germination and pollen tube growth. This research provides new research directions for flavonoids in reproductive development.

The pigeon pea CcCIPK14-CcCBL1 pair positively modulates drought tolerance by enhancing flavonoid biosynthesis

Calcineurin B-like (CBL)-interacting protein kinases (CIPKs) play a central role in Ca²⁺ signalling and promote drought tolerance in plants. The CIPK gene family in pigeon pea (Cajanus cajan L.), a major food crop affected by drought, has not previously been characterised. Here, we identified 28 CIPK genes in the pigeon pea genome. Five CcCIPK genes were strongly upregulated in roots upon drought treatment and were selected for further characterisation. Overexpression of CcCIPK13 and CcCIPK14 increased survival rates by two- to three-fold relative to controls after 14 days of drought. Furthermore, the three major flavonoids, genistin, genistein and apigenin, were significantly upregulated in the same transgenic plants. Using CcCIPK14 as bait, we performed a yeast two-hybrid screen and identified six interactors, including CcCBL1. CcCIPK14 exhibited autophosphorylation and phosphorylation of CcCBL1 in vitro. CcCBL1-overexpressed plants displayed higher survival rates upon drought stress as well as higher expression of flavonoid biosynthetic genes and flavonoid content. CcCIPK14-overexpressed plants in which CcCBL1 transcript levels were reduced by RNA interference had lower survival rates, which indicated CcCBL1 in the same pathway as CcCIPK14. Together, our results demonstrate a role for the CcCIPK14-CcCBL1 complex in drought stress tolerance through the regulation of flavonoid biosynthesis in pigeon pea.

Hyperoside regulates its own biosynthesis via MYB30 in promoting reproductive development and seed set in okra

Flavonoids are secondary metabolites that play important roles in fruit and vegetable development. Here, we examined the function of hyperoside, a unique flavonoid in okra (Abelmoschus esculentus), known to promote both flowering and seed set. We showed that the exogenous application of hyperoside significantly improved pollen germination rate and pollen tube growth by almost 50%, resulting in a 42.7% increase in the seed set rate. Of several genes induced by the hyperoside treatment, AeUF3GaT1, which encodes an enzyme that catalyzes the last step of hyperoside biosynthesis, was the most strongly induced. The transcription factor AeMYB30 enhanced AeUFG3aT1 transcription by directly binding to the AeUFG3aT1 promoter. We studied the effect of the hyperoside application on the expression of 10 representative genes at four stages of reproductive development, from pollination to seed maturity. We firstly developed an efficient transformation system that uses seeds as explants to study the roles of AeMYB30 and AeUFG3aT1. Overexpression of AeMYB30 or AeUF3GaT1 promoted seed development. Moreover, exogenous application of hyperoside partially restored the aberrant phenotype of AeUF3GaT1 RNA-interference plants. Thus, hyperoside promotes seed set in okra via a pathway involving AeUF3GaT and AeMYB30, and the exogenous application of this flavonoid is a simple method that can be used to improve seed quality and yield in okra.