Search

During the domestication of crops, seed dormancy has been reduced or eliminated to encourage faster and more consistent germination. This alteration makes cultivated crops particularly vulnerable to pre-harvest sprouting, which occurs when mature crops are subjected to adverse environmental conditions, such as excessive rainfall or high humidity. Consequently, some seeds may bypass the normal dormancy period and begin to germinate while still attached to the mother plant before harvest. Grains affected by pre-harvest sprouting are characterized by increased levels of α-amylase activity, resulting in poor processing quality and immediate grain downgrading. In the agriculture industry, pre-harvest sprouting causes annual economic losses exceeding USD 1 billion worldwide. This premature germination is influenced by a complex interplay of genetic, biochemical, and molecular factors closely linked to environmental conditions like rainfall. However, the exact mechanism behind this process is still unclear. Unlike pre-harvest sprouting, vivipary refers to the germination process and the activation of α-amylase during the soft dough stage, when the grains are still immature. Mature seeds with reduced levels of ABA or impaired ABA signaling (weak dormancy) are more susceptible to pre-harvest sprouting. While high seed dormancy can enhance resistance to pre-harvest sprouting, it can lead to undesirable outcomes for most crops, such as non-uniform seedling establishment after sowing. Thus, resistance to pre-harvest sprouting is crucial to ensuring productivity and sustainability and is an agronomically important trait affecting yield and grain quality. On the other hand, seed color is linked to sprouting resistance; however, the genetic relationship between both characteristics remains unresolved. The identification of mitogen-activated protein kinase kinase-3 (MKK3) as the gene responsible for pre-harvest sprouting-1 (Phs-1) represents a significant advancement in our understanding of how sprouting in wheat is controlled at the molecular and genetic levels. In seed maturation, Viviparous-1 (Vp-1) plays a crucial role in managing pre-harvest sprouting by regulating seed maturation and inhibiting germination through the suppression of α-amylase and proteases. Vp-1 is a key player in ABA signaling and is essential for the activation of the seed maturation program. Mutants of Vp-1 exhibit an unpigmented aleurone cell layer and exhibit precocious germination due to decreased sensitivity to ABA. Recent research has also revealed that TaSRO-1 interacts with TaVp-1, contributing to the regulation of seed dormancy and resistance to pre-harvest sprouting in wheat. The goal of this review is to emphasize the latest research on pre-harvest sprouting in crops and to suggest possible directions for future studies. [ABSTRACT FROM AUTHOR]

SUMMARY: The aleurone layer in cereal grains acts as a major reservoir of essential mineral nutrients, significantly influencing seed germination. However, the molecular mechanism underlying the redistribution of nutrients from the aleurone layer in the germinating seed is still not well understood. Here, in rice, we identified a plasma membrane (PM) localized magnesium transporter, MAGNESIUM RELEASE TRANSPORTER 3 (MGR3), is critical for seed germination. OsMGR3 is predominantly expressed in the aleurone layer cells of endosperm, facilitating magnesium remobilization during germination. Non‐invasive Micro‐test Technology assay data demonstrated that the loss‐of‐function of OsMGR3 restrained magnesium efflux from the aleurone layer. In the embryo/endosperm grafting experiment, we observed that the mutation of OsMGR3 in the aleurone layer suppressed the growth and differentiation of the embryo during germination. Furthermore, magnesium fluorescence imaging revealed the osmgr3 mutant seeds showed impaired exportation of aleurone layer‐stored magnesium to the embryo, consequently delaying germination. Importantly, we discovered that disrupting OsMGR3 could inhibit pre‐harvest sprouting without affecting rice yield and quality. Therefore, the magnesium efflux transporter OsMGR3 in the aleurone layer represents a promising genetic target for future agronomic trait improvement. Significance Statement: The molecular mechanism responsible for redistributing nutrients from the aleurone layer in germinating seeds is not well understood. In this study, we have identified a plasma membrane‐localized magnesium transporter that facilitates the remobilization of magnesium stored in the aleurone layer for seed germination in rice. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) is one of the important abiotic stresses in mungbean which significantly reduces yield and quality of the produce. This study was conducted to evaluate the genetic variability for tolerance to pre-harvest sprouting in diverse mungbean genotypes while simultaneously deciphering the association of yield contributing traits with PHS. Eighty-three diverse mungbean genotypes (23 released varieties, 23 advanced breeding lines and 37 exotic germplasm lines) were investigated for tolerance to PHS, water imbibition capacities by pods, pod and seed physical traits. Wide variation in PHS was recorded which ranged between 17.8% to 81% (mean value 54.34%). Germplasm lines exhibited higher tolerance to PHS than the high-yielding released varieties. Correlation analysis revealed PHS to be positively associated with water imbibition capacity by pods (r = 0.21) and germinated pod % (r = 0.78). Pod length (r = −0.13) and seeds per pod (r = −0.13) were negatively influencing PHS. Positive associations between PHS and water imbibition capacity by pods, germinated pod % and 100-seed weight was further confirmed by multivariate analysis. Small-seeded genotypes having 100-seed weight <3 g exhibited higher tolerance to PHS compared to bold-seeded genotypes having 100-seed weight more than 3.5 g. Fresh seed germination among the selected PHS tolerant and susceptible genotypes ranged from 42% (M 204) to 98% (Pusa 1131). A positive association (r = 0.79) was recorded between fresh seed germination and PHS. Genotypes M 1255, M 145, M 422, M 1421 identified as potential genetic donors against PHS could be utilized in mungbean breeding programs. [ABSTRACT FROM AUTHOR]

Rice is a significant staple crop that provides food and livelihoods for millions of people worldwide. However, climate change and frequent cyclonic storms with heavy rains during grain maturation periods have led to a significant reduction in rice yield and quality (20–30%) due to pre-harvest sprouting (PHS) damage. PHS has become a widespread issue globally, resulting in significant economic losses for Indian farmers, amounting to billions of rupees annually and severely impacting the country’s economy. Developing protocol and PHS-resistant rice genotypes is essential to mitigate the significant economic losses experienced by farmers and meet the growing demand for food grain with the increasing population. This study was aimed to developing the efficient protocol to identify PHS-resistant rice genotypes by evaluating 96 genotypes under laboratory and field conditions at 20, 25, 30, 35 and 40 days after flowering (DAF). To evaluate the PHS resistant genotypes we have developed the efficient and standard protocol for the present study. The results showed a positive correlation between phenotypic responses under laboratory and field conditions. Based on the germination percentage exhibited under laboratory and field conditions, the genotypes were grouped into four clusters using K-clustering and dendrogram clustering analysis. Out of 96 genotypes evaluated 19 grouped as highly susceptible (45 to 88%), 14 were moderately susceptible (10 to 45%), 51 were moderately resistant (0.10 to 10.00%), and 12 were highly resistant with zero percent germination at all flowering stages. The study also evaluated the genotypes for days to germination from 20 to 40 DAF. The highly susceptible genotypes germinated earlier (3 days) than moderately susceptible and resistant genotypes (4 to 6 days). Zero days were assigned to highly resistant genotypes since no germination was recorded. In nutshell, the novel PHS-resistant rice genotypes identified in this study could serve as donors for future crop improvement programs. [ABSTRACT FROM AUTHOR]

The rice cultivar ‘Chamdongjin’ exhibits a distinctively large grain size and excellent eating quality but is weak with regard to pre-harvest sprouting (PHS), requiring genetic improvement. In contrast, the premium-quality rice cultivar ‘Younghojinmi’ exhibits strong PHS tolerance. This study conducted quantitative trait loci (QTL) analysis on PHS and low-temperature germinability (LTG) using recombinant inbred lines derived from a cross between ‘Chamdongjin’ and ‘Younghojinmi’ to elucidate the genetic factors. Thus, an elite line with improved PHS tolerance was selected. QTL analysis revealed that qPHS3 and qLTG3 were associated with PHS and LTG, respectively, and the candidate gene was identified as qLTG3-1. The loss-of-function allele qltg3-1 in ‘Younghojinmi’ enhanced PHS tolerance compared to the functional allele qLTG3-1 in ‘Chamdongjin,’ but it also showed a trade-off relationship by decreasing LTG. CY_RILs carrying qltg3-1 exhibited lower PHS and LTG rates of 17.9% and 41.6%, respectively, compared to 44.1% and 55.7%, respectively, for CY_RILs with qLTG3-1. The elite line, CY_RIL79, carrying qltg3-1, was selected from CY_RIL. This line was recognized for its PHS tolerance while maintaining the key agricultural traits of ‘Chamdongjin,’ thus designated ‘Jeonju697.’ ‘Jeonju697’ is expected to be utilized as a practical alternative for addressing the issue of enhancing PHS tolerance in ‘Chamdongjin’; however, considering its weak LTG, it is desirable to improve this trait through further breeding efforts. [ABSTRACT FROM AUTHOR]

SUMMARY: Pre‐harvest sprouting (PHS) is a significant threat to global food security due to its association with losses in both yield and quality. Among the genes involved in PHS resistance in wheat, PHS‐3D (TaMyb10‐D) plays a crucial role. Here, we characterized the sequence variations of TaMyb10 genes in 416 bread wheat and 302 Aegilops tauschii accessions. Within TaMyb10‐A sequences, we identified a deletion ranging from 214 to 305 bp in the signal and amino acid coding region, present in 61.3% of the accessions. Similarly, 79.3% of the TaMyb10‐B sequences within the third exon region exhibited a 19 bp deletion. Additionally, 40.8% of the accessions lacked the 2.4 Mb fragment (in/del mutations) on Chr3D, where TaMyb10‐D/PHS‐3D was located. Interestingly, the geographical distribution of accessions showed little correlation with the divergence of TaMyb10. TaMyb10‐A‐IIIDele, TaMyb10‐B‐IVDele, and TaMyb10‐D‐VDele genotypes were prevalent in wheat populations across continents. Despite their structural variations, the five distinct protein types exhibited comparable ability to bind the promoters of downstream genes in the flavonoid and ABA pathways, such as CHS, DFR, and NCED. Furthermore, the combination of TaMyb10 homologs was significantly associated with grain color and germination percentages. Accessions exclusively harboring TaMyb10‐D displayed red seed color and reduced germination percentages, indicating the predominant role of TaMyb10‐D compared to TaMyb10‐A and TaMyb10‐B. This comprehensive investigation enhances our understanding of the structural variations and functional divergence of TaMyb10, providing valuable insights and resources for improving PHS resistance in wheat. Significance Statement: TaPHS‐3D (TaMyb10‐D) plays a crucial role among the genes implicated in pre‐harvest sprouting resistance in wheat. Our study revealed a significant correlation between the combination of TaMyb10 homologs, grain color, and germination. Notably, TaMyb10‐D exhibited a more substantial functional impact than TaMyb10‐A and TaMyb10‐B. These findings deepen our understanding of the structural variations and functional distinctions within TaMyb10, providing valuable insights and resources for improving PHS resistance in wheat. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) stands as a significant cereal crop globally, including in Korea, where its consumption reached 35.7 kg per capita in 2023. In the southern regions of Korea, wheat cultivation follows paddy rice, with harvesting typically occurring during the rainy season in mid-June. This timing, coupled with the high humidity and unpredictable rainfall, often leads to pre-harvest sprouting and subsequent deterioration in flour quality. To assess the impact of rain on flour quality, an artificial rain treatment was administered 45 days after heading in an open field greenhouse, followed by flour quality analysis. The color measurement revealed an increase in the L* parameter, indicative of enhanced kernel vitreousness, attributed to endosperm starch degradation via alpha-amylase activation induced by water absorption. Moreover, significant changes were observed in ash content and the gluten index within the wetted group, resulting in decreased dough strength and stability, ultimately leading to a reduction in loaf volume. Consequently, it is recommended that wheat be harvested 4–7 days after reaching the physiological maturity stage to avoid the rainy season and ensure the production of high-quality wheat. [ABSTRACT FROM AUTHOR]

Abstract Background Class III peroxidases (PODs) perform crucial functions in various developmental processes and responses to biotic and abiotic stresses. However, their roles in wheat seed dormancy (SD) and germination remain elusive. Results Here, we identified a wheat class III POD gene, named TaPer12-3A, based on transcriptome data and expression analysis. TaPer12-3A showed decreasing and increasing expression trends with SD acquisition and release, respectively. It was highly expressed in wheat seeds and localized in the endoplasmic reticulum and cytoplasm. Germination tests were performed using the transgenic Arabidopsis and rice lines as well as wheat mutant mutagenized with ethyl methane sulfonate (EMS) in Jing 411 (J411) background. These results indicated that TaPer12-3A negatively regulated SD and positively mediated germination. Further studies showed that TaPer12-3A maintained H2O2 homeostasis by scavenging excess H2O2 and participated in the biosynthesis and catabolism pathways of gibberellic acid and abscisic acid to regulate SD and germination. Conclusion These findings not only provide new insights for future functional analysis of TaPer12-3A in regulating wheat SD and germination but also provide a target gene for breeding wheat varieties with high pre-harvest sprouting resistance by gene editing technology.

Abstract Background B-box (BBX) proteins are a type of zinc finger proteins containing one or two B-box domains. They play important roles in development and diverse stress responses of plants, yet their roles in wheat remain unclear. Results In this study, 96 BBX genes were identified in the wheat genome and classified into five subfamilies. Subcellular localization prediction results showed that 68 TaBBXs were localized in the nucleus. Protein interaction prediction analysis indicated that interaction was one way that these proteins exerted their functions. Promoter analysis indicated that TaBBXs may play important roles in light signal, hormone, and stress responses. qRT-PCR analysis revealed that 14 TaBBXs were highly expressed in seeds compared with other tissues. These were probably involved in seed dormancy and germination, and their expression patterns were investigated during dormancy acquisition and release in the seeds of wheat varieties Jing 411 and Hongmangchun 21, showing significant differences in seed dormancy and germination phenotypes. Subcellular localization analysis confirmed that the three candidates TaBBX2-2 A, TaBBX4-2 A, and TaBBX11-2D were nuclear proteins. Transcriptional self-activation experiments further demonstrated that TaBBX4-2A was transcriptionally active, but TaBBX2-2A and TaBBX11-2D were not. Protein interaction analysis revealed that TaBBX2-2A, TaBBX4-2A, and TaBBX11-2D had no interaction with each other, while TaBBX2-2A and TaBBX11-2D interacted with each other, indicating that TaBBX4-2A may regulate seed dormancy and germination by transcriptional regulation, and TaBBX2-2A and TaBBX11-2D may regulate seed dormancy and germination by forming a homologous complex. Conclusions In this study, the wheat BBX gene family was identified and characterized at the genomic level by bioinformatics analysis. These observations provide a theoretical basis for future studies on the functions of BBXs in wheat and other species.

The association between pre-harvest sprouting (PHS) and seed coat color has long been recognized. Red-grained wheats generally exhibit greater PHS resistance compared to white-grained wheat, although variability in PHS resistance exists within red-grained varieties. Here, we conducted a genome-wide association study on a panel consisting of red-grained wheat varieties, aimed at uncovering genes that modulate PHS resistance and red color components of seed coat using digital image processing. Twelve loci associated with PHS traits were identified, nine of which were described for the first time. Genetic loci marked by SNPs AX-95172164 (chromosome 1B) and AX-158544327 (chromosome 7D) explained approximately 25% of germination index variance, highlighting their value for breeding PHS-resistant varieties. The most promising candidate gene for PHS resistance was TraesCS6B02G147900, encoding a protein involved in aleurone layer morphogenesis. Twenty-six SNPs were significantly associated with grain color, independently of the known Tamyb10 gene. Most of them were related to multiple color characteristics. Prioritization of genes within the revealed loci identified TraesCS1D03G0758600 and TraesCS7B03G1296800, involved in the regulation of pigment biosynthesis and in controlling pigment accumulation. In conclusion, our study identifies new loci associated with grain color and germination index, providing insights into the genetic mechanisms underlying these traits. [ABSTRACT FROM AUTHOR]

Background: B-box (BBX) proteins are a type of zinc finger proteins containing one or two B-box domains. They play important roles in development and diverse stress responses of plants, yet their roles in wheat remain unclear. Results: In this study, 96 BBX genes were identified in the wheat genome and classified into five subfamilies. Subcellular localization prediction results showed that 68 TaBBXs were localized in the nucleus. Protein interaction prediction analysis indicated that interaction was one way that these proteins exerted their functions. Promoter analysis indicated that TaBBXs may play important roles in light signal, hormone, and stress responses. qRT-PCR analysis revealed that 14 TaBBXs were highly expressed in seeds compared with other tissues. These were probably involved in seed dormancy and germination, and their expression patterns were investigated during dormancy acquisition and release in the seeds of wheat varieties Jing 411 and Hongmangchun 21, showing significant differences in seed dormancy and germination phenotypes. Subcellular localization analysis confirmed that the three candidates TaBBX2-2 A, TaBBX4-2 A, and TaBBX11-2D were nuclear proteins. Transcriptional self-activation experiments further demonstrated that TaBBX4-2A was transcriptionally active, but TaBBX2-2A and TaBBX11-2D were not. Protein interaction analysis revealed that TaBBX2-2A, TaBBX4-2A, and TaBBX11-2D had no interaction with each other, while TaBBX2-2A and TaBBX11-2D interacted with each other, indicating that TaBBX4-2A may regulate seed dormancy and germination by transcriptional regulation, and TaBBX2-2A and TaBBX11-2D may regulate seed dormancy and germination by forming a homologous complex. Conclusions: In this study, the wheat BBX gene family was identified and characterized at the genomic level by bioinformatics analysis. These observations provide a theoretical basis for future studies on the functions of BBXs in wheat and other species. [ABSTRACT FROM AUTHOR]

Background: Class III peroxidases (PODs) perform crucial functions in various developmental processes and responses to biotic and abiotic stresses. However, their roles in wheat seed dormancy (SD) and germination remain elusive. Results: Here, we identified a wheat class III POD gene, named TaPer12-3A, based on transcriptome data and expression analysis. TaPer12-3A showed decreasing and increasing expression trends with SD acquisition and release, respectively. It was highly expressed in wheat seeds and localized in the endoplasmic reticulum and cytoplasm. Germination tests were performed using the transgenic Arabidopsis and rice lines as well as wheat mutant mutagenized with ethyl methane sulfonate (EMS) in Jing 411 (J411) background. These results indicated that TaPer12-3A negatively regulated SD and positively mediated germination. Further studies showed that TaPer12-3A maintained H2O2 homeostasis by scavenging excess H2O2 and participated in the biosynthesis and catabolism pathways of gibberellic acid and abscisic acid to regulate SD and germination. Conclusion: These findings not only provide new insights for future functional analysis of TaPer12-3A in regulating wheat SD and germination but also provide a target gene for breeding wheat varieties with high pre-harvest sprouting resistance by gene editing technology. [ABSTRACT FROM AUTHOR]

This editorial titled "Seed dormancy, germination, and pre-harvest sprouting, volume II" discusses the issue of pre-harvest sprouting (PHS) in crops, specifically in cereal crops. PHS occurs when seeds germinate prematurely in the mother plants before harvest, leading to poor grain quality and economic losses. The editorial emphasizes the importance of understanding the genetic and molecular basis of seed dormancy and PHS and highlights recent advancements in research on this topic. It also mentions the role of plant hormones such as abscisic acid (ABA) and gibberellin acid (GA) in seed dormancy and germination. The document further discusses recent research on seed dormancy, germination, and PHS in crops like quinoa and mungbean, providing insights into the molecular mechanisms and genetic factors that influence these processes. The authors stress the need for further research in areas such as genome editing, multi-omics approaches, and the interaction of environmental factors with PHS. [Extracted from the article]

Resistance to pre-harvest sprouting (PHS) is an agronomically important trait affecting the yield and grain quality of bread wheat. PHS resistance depends both on environmental factors and the genotypic and phenotypic properties of wheat varieties. It is known that wheat varieties with red-grain are more resistant to PHS than white-grain varieties. However, at present there are no methodological approaches that allow to unambiguously distinguish red-grain varieties according to the level of PHS resistance. The purpose of the study was to compare different methods for efficient differentiation of soft winter wheat (Triticum aestivum L.) varieties for resistance to PHS. The germination index (GI), α-amylase activity (AAA), a digital grade of the grain color and genetic bases of the wheat varieties the grain was determined in 164 winter wheat, among them 156 were red-grain. The studies were carried out at the late milk/hard dough (LM/HD; GS77-GS87) stage and the hard grain (HG; GS92-GS93) stage. Based on the dynamics of GI it was found that late LM/HD stage is the most suitable for GI evaluation. AAA was performed using the Ceralpha method and falling number (FN) evaluation. An increase in the level of AAA during grain ripening of wheat varieties was shown. A negative correlation was found between GI and FN, FN and AAA. Using the Lab color model to assess the color variation of the grain coat allow to identify 3 variants of grain color. Genetic base of wheat varieties was analyzed by means of allelic composition of the Tamyb10 gene, which participate in the formation of the red color of grain. The results indicated that digital analysis and allelic composition of the Tamyb10 cannot be used as additional criterion for separation of red-grain wheat varieties for resistance to PHS. This is despite the fact that the numerous group of the varieties contain two or more dominant Tamyb10 gene. In general, a comparison of varieties by all three parameters allow to identify a group of varieties that are most PHS resistant. This group consist of 73 red-grain varieties out of 156, while no white-grain PHS-resistant varieties were identified. [ABSTRACT FROM AUTHOR]

Rice grains are the major source of nutrition for more than half of the world's population. With increased frequencies of cyclones in the last decade during grain maturation stage of rice crop, most of the rice cultivars in lowland ecologies are getting affected by pre harvest sprouting due to flash flooding and incessant rains. Significant economic loss is incurred in the global food grain industry of cereals due to pre-harvest sprouting (PHS). It is very important to develop climate resilient varieties with PHS resistant traits introgressed in them. Well characterized PHS resistant rice genotypes with optimal dormancy that can serve as donors are need of the hour. We conducted an experiment to identify PHS resistant genotypes, and also determine to their physiological and biochemical characteristics. 96 diverse rice genotypes were evaluated for PHS resistance from 20 to 40 days after flowering (DAF). Based on their response, 16 contrasting genotypes were identified from 96 genotypes to further study the underlying mechanism of PHS resistance. The results revealed that, susceptible genotypes (8) exhibited very high germination percentage (4 to 87.5%), while resistant genotypes (8) exhibited zero germination at all the stages of study. Susceptible genotypes had higher levels of reactive oxygen species (H2O2 and O2−) and malondialdehyde (MDA) in their leaves (flag leaf) and seeds than resistant genotypes indicating a better stress protection mechanism in the resistant genotypes. The ability to imbibe moisture upon treatment also varied among the contrasting genotypes. In a nutshell, the present study revealed that better ROS scavenging mechanism, lower lipid peroxidation along with lesser moisture absorption capacity could have contributed to PHS resistance in the resistant genotypes. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) is one of the important abiotic stresses in mungbean which significantly reduces yield and quality of the produce. This study was conducted to evaluate the genetic variability for tolerance to pre-harvest sprouting in diverse mungbean genotypes while simultaneously deciphering the association of yield contributing traits with PHS. Eighty-three diverse mungbean genotypes (23 released varieties, 23 advanced breeding lines and 37 exotic germplasm lines) were investigated for tolerance to PHS, water imbibition capacities by pods, pod and seed physical traits. Wide variation in PHS was recorded which ranged between 17.8% to 81% (mean value 54.34%). Germplasm lines exhibited higher tolerance to PHS than the high-yielding released varieties. Correlation analysis revealed PHS to be positively associated with water imbibition capacity by pods (r = 0.21) and germinated pod % (r = 0.78). Pod length (r = −0.13) and seeds per pod (r = −0.13) were negatively influencing PHS. Positive associations between PHS and water imbibition capacity by pods, germinated pod % and 100-seed weight was further confirmed by multivariate analysis. Small-seeded genotypes having 100-seed weight

Abstract Rapeseed (Brassica napus L.) with short or no dormancy period are easy to germinate before harvest (pre-harvest sprouting, PHS). PHS has seriously decreased seed weight and oil content in B. napus. Short-chain dehydrogenase/ reductase (SDR) genes have been found to related to seed dormancy by promoting ABA biosynthesis in rice and Arabidopsis. In order to clarify whether SDR genes are the key factor of seed dormancy in B. napus, homology sequence blast, protein physicochemical properties, conserved motif, gene structure, cis-acting element, gene expression and variation analysis were conducted in present study. Results shown that 142 BnaSDR genes, unevenly distributed on 19 chromosomes, have been identified in B. napus genome. Among them, four BnaSDR gene clusters present in chromosome A04、A05、C03、C04 were also identified. These 142 BnaSDR genes were divided into four subfamilies on phylogenetic tree. Members of the same subgroup have similar protein characters, conserved motifs, gene structure, cis-acting elements and tissue expression profiles. Specially, the expression levels of genes in subgroup A, B and C were gradually decreased, but increased in subgroup D with the development of seeds. Among seven higher expressed genes in group D, six BnaSDR genes were significantly higher expressed in weak dormancy line than that in nondormancy line. And the significant effects of BnaC01T0313900ZS and BnaC03T0300500ZS variation on seed dormancy were also demonstrated in present study. These findings provide a key information for investigating the function of BnaSDRs on seed dormancy in B. napus.

During the domestication of crops, seed dormancy has been reduced or eliminated to encourage faster and more consistent germination. This alteration makes cultivated crops particularly vulnerable to pre-harvest sprouting, which occurs when mature crops are subjected to adverse environmental conditions, such as excessive rainfall or high humidity. Consequently, some seeds may bypass the normal dormancy period and begin to germinate while still attached to the mother plant before harvest. Grains affected by pre-harvest sprouting are characterized by increased levels of α-amylase activity, resulting in poor processing quality and immediate grain downgrading. In the agriculture industry, pre-harvest sprouting causes annual economic losses exceeding USD 1 billion worldwide. This premature germination is influenced by a complex interplay of genetic, biochemical, and molecular factors closely linked to environmental conditions like rainfall. However, the exact mechanism behind this process is still unclear. Unlike pre-harvest sprouting, vivipary refers to the germination process and the activation of α-amylase during the soft dough stage, when the grains are still immature. Mature seeds with reduced levels of ABA or impaired ABA signaling (weak dormancy) are more susceptible to pre-harvest sprouting. While high seed dormancy can enhance resistance to pre-harvest sprouting, it can lead to undesirable outcomes for most crops, such as non-uniform seedling establishment after sowing. Thus, resistance to pre-harvest sprouting is crucial to ensuring productivity and sustainability and is an agronomically important trait affecting yield and grain quality. On the other hand, seed color is linked to sprouting resistance; however, the genetic relationship between both characteristics remains unresolved. The identification of mitogen-activated protein kinase kinase-3 (MKK3) as the gene responsible for pre-harvest sprouting-1 (Phs-1) represents a significant advancement in our understanding of how sprouting in wheat is controlled at the molecular and genetic levels. In seed maturation, Viviparous-1 (Vp-1) plays a crucial role in managing pre-harvest sprouting by regulating seed maturation and inhibiting germination through the suppression of α-amylase and proteases. Vp-1 is a key player in ABA signaling and is essential for the activation of the seed maturation program. Mutants of Vp-1 exhibit an unpigmented aleurone cell layer and exhibit precocious germination due to decreased sensitivity to ABA. Recent research has also revealed that TaSRO-1 interacts with TaVp-1, contributing to the regulation of seed dormancy and resistance to pre-harvest sprouting in wheat. The goal of this review is to emphasize the latest research on pre-harvest sprouting in crops and to suggest possible directions for future studies.

Grain dormancy of wheat is closely associated with grain color: red-grained lines show higher dormancy than white-grained lines. The production of red pigments is regulated by R-1, Tamyb10 gene. However, the relation between grain color and dormancy remains unknown. For this study, we generated transgenic lines which were introduced a DNA fragment containing Tamyb10-D1 gene and its a 2 kb promoter including the 5′ untranslated region into white-grained wheat. Transgenic lines showed red-grained and higher dormant traits. Contents of plant hormones and gene expression of embryos at 30 days after pollination were examined in a wild type and a transgenic line. No differences were observed in the contents of plant hormones, but several genes are differentially expressed between these lines. One differentially expressed gene, TaLTP2.128, is a member of non-specific lipid transfer proteins. It was expressed higher in white grains than in red grains. A putative amino acid sequence showed similarity to that of OsHyPRP5, which is identified as QTL controlling low-temperature germinability in rice. Expression of TaLTP2.128 was increased by grain imbibition. The increasing levels were higher not only in other white-grained lines, but also in non-dormant red-grained lines. TaLTP2.128 was expressed at a quite early stage of germination. These study findings indicate that Tamyb10 regulates dormancy release by the modification of TaLTP2.128 acting as trigger of germination. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) is a condition triggered by environmental factors, particularly prevalent in humid conditions, leading to substantial yield losses in black gram. While the potential for genotypic PHS tolerance exists, it has not been thoroughly assessed in black gram. Hence, the present study aimed to delve into the genetic variation for PHS tolerance in diverse black gram (Vigna mungo (L.) Hepper) germplasm, and also to comprehend the impact of various physical and physiological traits on PHS. A diverse set of 112 black gram accessions collected across the phytogeographical zones of India were examined for their seed and pod characteristics. Water absorption by pods and seeds and fresh-seed germination was calculated by following the standard procedure given by the International Seed Testing Association. The alpha-amylase activity was measured on dry seeds (0 h), 24 h, 48 h, and 72 h after germination of each accession, using a UV-VIS spectrophotometer, and hard-seededness was measured using a texture analyzer machine. The results showed a wide range in PHS tolerance and FSG, and 13 accessions were found to be PHS-tolerant (PHS value < 10%). An indicator of PHS, seed germination in a pod, ranged from 2.75% in IC485641 (highly tolerant to PHS) to 95.85% in IC530501 (highly susceptible to PHS). Correlation and multivariate analysis revealed that PHS was positively correlated with water imbibition by pod and seed, fresh-seed germination and alpha-amylase activity. PHS-tolerant accessions showed a slow increase in alpha-amylase activity, in contrast to PHS-susceptible accessions. The utilization of alpha-amylase activity as a biochemical marker has the potential for evaluating PHS tolerance across various black gram accessions. The identified PHS-tolerant accessions can be used as donors in crop improvement programs aimed at developing PHS-tolerant black gram varieties. [ABSTRACT FROM AUTHOR]

Domestication and extensive selection in the development of modern, high-yielding commercial groundnut cultivars have resulted in the selection of an undesirable trait known as in situ germination, which is also referred to as the pre-harvest sprouting of seeds. This is particularly prevalent in regions where humid weather coincides with the harvest season. Delayed harvesting and pre-sprouting can cause production losses and increase the chances of aflatoxin contamination, thereby impeding the quality and kernel yield. Breeding early maturing groundnut cultivars with 2–3 weeks of fresh seed dormancy, particularly in Spanish-type cultivars, enhances the sustainability of agriculture. In this context, we conducted a comprehensive evaluation of a groundnut mini-core collection, a major resource for genetic diversity, for fresh seed dormancy using an in vitro germination assay for two seasons, viz., rainy 2022 and post-rainy 2022–2023 at ICRISAT (Hyderabad). To enhance the effectiveness and accuracy of traditional breeding methods via the use of markers for marker-assisted selection, we performed molecular screening of the mini-core accessions using two allele-specific markers. The GMFSD1 marker was successfully validated by effectively differentiating dormant and non-dormant genotypes. By employing phenotypic and marker data, we identified a set of accessions, viz., ICG 5827 (Virginia Runner), ICG 11457 (Virginia Runner), ICG 7000 (Virginia Bunch), and ICG 11322 (Virginia Bunch) of sub spp. hypogaea var. hypogaea and ICG 9809 (Spanish Bunch) of sub spp. fastigiata var. vulgaris that exhibited a fresh seed dormancy period ranging from 2 to 3 weeks. These identified accessions hold potential as donors in breeding programs that are designed to address the groundnut production needs in various cropping systems across different countries. The validated marker, particularly GMFSD1, demonstrated considerable potential for facilitating faster breeding of groundnut cultivars with the desired dormancy using marker-assisted selection. This research provides a foundation to expediting groundnut breeding programs and offers opportunities to mitigate pre-harvest sprouting, ultimately improving seed quality and productivity in groundnut-producing regions. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting refers to the phenomenon that rice tends to induce seed germination on the spike if it encounters continuous cloudy and rainy weather or high-temperature and humid environmental conditions before harvest. Pre-harvest sprouting leads to decreased seed vigor and quality of rice, resulting in huge losses to rice production. In addition to expanding the screening of pre-harvest sprouting mutants, excavating and cloning some new genes controlling pre-harvest sprouting and analyzing their spike germination regulatory mechanisms are important tasks for breeding rice for pre-harvest sprouting resistance. During the process of pre-harvest sprouting, rice amylase activity is enhanced, soluble sugar content is elevated, and the content and balance of phytohormones ABA and GA in rice seeds are the key factors determining pre-harvest sprouting. Some key genes such as OsVP1 control rice seed dormancy through the ABA signaling pathway, while GA regulates seed germination through the activation of GA-associated transcription factors. The article reviews the four areas, i.e., internal physiological factors and environmental conditions of rice pre-harvest sprouting, genetic mechanisms of rice pre-harvest sprouting, molecular mechanisms of rice pre-harvest sprouting, and trait improvement of rice pre-harvest sprouting, and thus aiming to provide theoretical references for the selection of varieties that are resistant to pre-harvest sprouting in rice. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS), the germination of seeds on the plant prior to harvest, poses significant challenges to agriculture. It not only reduces seed and grain yield, but also impairs the commodity quality of the fruit, ultimately affecting the success of the subsequent crop cycle. A deeper understanding of PHS is essential for guiding future breeding strategies, mitigating its impact on seed production rates and the commercial quality of fruits. PHS is a complex phenomenon influenced by genetic, physiological, and environmental factors. Many of these factors exert their influence on PHS through the intricate regulation of plant hormones responsible for seed germination. While numerous genes related to PHS have been identified in food crops, the study of PHS in vegetable crops is still in its early stages. This review delves into the regulatory elements, functional genes, and recent research developments related to PHS in vegetable crops. Meanwhile, this paper presents a novel understanding of PHS, aiming to serve as a reference for the study of this trait in vegetable crops. [ABSTRACT FROM AUTHOR]

This study characterized six introgression lines obtained from crossing two winter bread wheat varieties Albena and Slaveya with the D-genome synthetic hexaploid wheat 530-1. Phenotypically, the lines differed from the parents, as five of them expressed red spike color versus line 45-5 producing new coloration, identified as striped or banded glume pigmentation. All lines were taller, with longer ears and spikelets, later in heading time and less productive in grain yield than both wheat parents. They showed some positive traits in the field: optimal test weight (78–80 kg/hl), high thousand kernel weight (48–51 g), low sprouted seeds (0.3–1.5%), and high falling number (314-350 s). Two lines (38-7 and 46-7) exceeded the parents in grain protein content. In the competitive variety trial, Albena showed significantly higher sprouted grains (4.1%) and extreme measurements for a percentage of germination (99.0%) and germination index (83.0%) in 2022. The data identified Albena as a wheat variety with pre-harvest sprouting susceptibility. Of the lines, only 45-5 stood out with the lowest germination values and appeared as a promising genotype with resistance to pre-harvest sprouting. The introgression lines exerted useful genetic diversity for the studied traits and could serve as resources for quality improvement in wheat breeding programs.

Abstract Pre-harvest sprouting (PHS) is one of the major threats to global food security as it significantly affects cereals’ production and quality. PHS tolerance depends on diverse factors, among which phytohormones and germination-inhibitory substances (GISs) play essential roles. However, in wheat, information related to GIS in the glume is scarce. Thus, we applied LC–MS/MS-based metabolomics analysis to explore the polyphenols and phytohormones profiles of two contrasting wheat genotypes, Lincang Hulled Wheat (LHW, PHS-resistant) and Yunmai53 (Yun53, PHS-highly susceptible). Physiological tests revealed that LHW PHS-resistance is not associated with the ability of its spikelet to prevent water absorption. The total polyphenol content of the spikes and shells of LHW was significantly higher than that of Yun53, respectively. In total, 214 phenolic compounds classified mainly into phenolic acids (42.52%), flavones (23.83%), and flavonoid carbonosides (16.36%) were identified. 180 differentially accumulated polyphenols (DAPs) were uncovered, including 168 up-regulated in LHW. 24 most up-regulated DAPs (Log2FC ≥ 8) were unveiled as potential candidate GISs. Of the identified phytohormones, abscisic acid, salicylic acid, and jasmonic acid exhibited significantly higher content in LHW compared to Yun53. Whereas, Yun53 contained significantly higher levels of ethylene and gibberellin than LHW. Our findings offer new resources for PHS control in wheat.

Pre-harvest sprouting (PHS) is one of the serious global issues in wheat production. Identification of quantitative trait loci (QTL) and closely-linked markers is greatly helpful for wheat improvement. In the present study, a recombinant inbred line (RIL) population derived from the cross of Zhongmai 578 (ZM578)/Jimai 22 (JM22) and parents were phenotyped in five environments and genotyped by the wheat 50 K single-nucleotide polymorphism (SNP) array. Two QTL of germination index (GI), QGI.caas-3A and QGI.caas-5A, were detected, explaining 4.33%–5.58% and 4.43%–8.02% of the phenotypic variances, respectively. The resistant effect of QGI.caas-3A was contributed by JM22, whereas that of QGI.caas.5A was from ZM578. The two QTL did not correspond to any previously identified genes or genetic loci for PHS-related traits according to their locations in the Chinese Spring reference genome, indicating that they are likely to be new loci for PHS resistance. Four kompetitive allele-specific PCR (KASP) markers K_AX-109605367and K_AX-179559687 flanking QGI.caas-3A, and K_AX-111258240 and K_AX-109402944 flanking QGI.caas-5A, were developed and validated in a natural population of 100 wheat cultivars. The distribution frequency of resistance alleles at Qphs.caas-3A and Qphs.caas-5A loci were 82.7% and 57.1%, respectively, in the natural population. These findings provide new QTL and tightly linked KASP markers for improvement of PHS resistance in wheat.

Vivipary also known as the precocious germination of seeds while still attached to the mother plant or fruit, it’s a relatively common phenomenon in angiosperms. However, the proliferating seedlings though interesting to look at, deter customers from eating the fruits. Similarly, vivipary is an adverse phenomenon for the agroindustry because of the lowest quality and palatability of fruits as well as lower seed set and viability. This paper highlights the taxonomic occurrence of vivipary in cereal and crop plants and the detrimental effects of this phenomenon in agricultural crops. According to literature sources, there are 38 fruit crops in which vivipary has been reported. The families Cucurbitaceae, Poaceae, Rutaceae, and Solanaceae include the fruits with the highest incidence of vivipary in the markets.

Pre-harvest sprouting (PHS) is one of the major threats to global food security as it significantly affects cereals’ production and quality. PHS tolerance depends on diverse factors, among which phytohormones and germination-inhibitory substances (GISs) play essential roles. However, in wheat, information related to GIS in the glume is scarce. Thus, we applied LC–MS/MS-based metabolomics analysis to explore the polyphenols and phytohormones profiles of two contrasting wheat genotypes, Lincang Hulled Wheat (LHW, PHS-resistant) and Yunmai53 (Yun53, PHS-highly susceptible). Physiological tests revealed that LHW PHS-resistance is not associated with the ability of its spikelet to prevent water absorption. The total polyphenol content of the spikes and shells of LHW was significantly higher than that of Yun53, respectively. In total, 214 phenolic compounds classified mainly into phenolic acids (42.52%), flavones (23.83%), and flavonoid carbonosides (16.36%) were identified. 180 differentially accumulated polyphenols (DAPs) were uncovered, including 168 up-regulated in LHW. 24 most up-regulated DAPs (Log2FC ≥ 8) were unveiled as potential candidate GISs. Of the identified phytohormones, abscisic acid, salicylic acid, and jasmonic acid exhibited significantly higher content in LHW compared to Yun53. Whereas, Yun53 contained significantly higher levels of ethylene and gibberellin than LHW. Our findings offer new resources for PHS control in wheat.Article highlights: 168 up-regulated phenolic compounds in the PHS-resistant wheat genotype were identified. Wheat PHS resistance is associated with higher polyphenols, ABA, JA, and SA contents. 24 potential germination inhibitory polyphenols were identified for further studies. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) stands as a significant cereal crop globally, including in Korea, where its consumption reached 35.7 kg per capita in 2023. In the southern regions of Korea, wheat cultivation follows paddy rice, with harvesting typically occurring during the rainy season in mid-June. This timing, coupled with the high humidity and unpredictable rainfall, often leads to pre-harvest sprouting and subsequent deterioration in flour quality. To assess the impact of rain on flour quality, an artificial rain treatment was administered 45 days after heading in an open field greenhouse, followed by flour quality analysis. The color measurement revealed an increase in the L* parameter, indicative of enhanced kernel vitreousness, attributed to endosperm starch degradation via alpha-amylase activation induced by water absorption. Moreover, significant changes were observed in ash content and the gluten index within the wetted group, resulting in decreased dough strength and stability, ultimately leading to a reduction in loaf volume. Consequently, it is recommended that wheat be harvested 4–7 days after reaching the physiological maturity stage to avoid the rainy season and ensure the production of high-quality wheat.

The association between pre-harvest sprouting (PHS) and seed coat color has long been recognized. Red-grained wheats generally exhibit greater PHS resistance compared to white-grained wheat, although variability in PHS resistance exists within red-grained varieties. Here, we conducted a genome-wide association study on a panel consisting of red-grained wheat varieties, aimed at uncovering genes that modulate PHS resistance and red color components of seed coat using digital image processing. Twelve loci associated with PHS traits were identified, nine of which were described for the first time. Genetic loci marked by SNPs AX-95172164 (chromosome 1B) and AX-158544327 (chromosome 7D) explained approximately 25% of germination index variance, highlighting their value for breeding PHS-resistant varieties. The most promising candidate gene for PHS resistance was TraesCS6B02G147900, encoding a protein involved in aleurone layer morphogenesis. Twenty-six SNPs were significantly associated with grain color, independently of the known Tamyb10 gene. Most of them were related to multiple color characteristics. Prioritization of genes within the revealed loci identified TraesCS1D03G0758600 and TraesCS7B03G1296800, involved in the regulation of pigment biosynthesis and in controlling pigment accumulation. In conclusion, our study identifies new loci associated with grain color and germination index, providing insights into the genetic mechanisms underlying these traits.

This study characterized six introgression lines obtained from crossing two winter bread wheat varieties Albena and Slaveya with the D-genome synthetic hexaploid wheat 530-1. Phenotypically, the lines differed from the parents, as five of them expressed red spike color versus line 45-5 producing new coloration, identified as striped or banded glume pigmentation. All lines were taller, with longer ears and spikelets, later in heading time and less productive in grain yield than both wheat parents. They showed some positive traits in the field: optimal test weight (78-80 kg/hl), high thousand kernel weight (48-51 g), low sprouted seeds (0.3-1.5%), and high falling number (314-350 s). Two lines (38-7 and 46-7) exceeded the parents in grain protein content. In the competitive variety trial, Albena showed significantly higher sprouted grains (4.1%) and extreme measurements for a percentage of germination (99.0%) and germination index (83.0%) in 2022. The data identified Albena as a wheat variety with pre-harvest sprouting susceptibility. Of the lines, only 45-5 stood out with the lowest germination values and appeared as a promising genotype with resistance to pre-harvest sprouting. The introgression lines exerted useful genetic diversity for the studied traits and could serve as resources for quality improvement in wheat breeding programs. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting is a serious problem in global agricultural production. After a long period of domestication, the dormancy level of cultivated crops is generally lower than that of wild ancestors. Although the shortening of dormancy period may increase the reproductive generation and agricultural production value of crops, premature dormancy release will cause crop sprouting before harvest, resulting in huge economic losses. In this paper, the physiological mechanism, QTL and genes, prevention and control of pre-harvest sprouting are systematically reviewed. It is believed that high water content is the precondition of rice seed germination and pre-harvest sprouting, during this process, the increases of amylase activity and soluble sugar content provide energy for pre-harvest sprouting; the contents of plant hormones ABA and GA in rice grains and the sensitivity of seeds to them are the key factors to determine the pre-harvest germination. In recent years, the excavation of QTL and its functional genes related to pre-harvest sprouting will provide an important basis for clarifying the mechanism of pre-harvest sprouting in rice and breeding resistant varieties. In the long run, through extensive evaluation of rice germplasm resources, especially searching for the lost dormancy genes in wild rice and local varieties, and gathering such genes through molecular breeding, breeding lines (varieties) resistant to sprouting, it is of great significance to solve the problem of sprouting, improve rice yield and quality, and ensure national food security.

Abstract Background Pre-harvest sprouting (PHS) is one of the most serious rice production constraints in areas where prolonged rainfall occurs during harvest. However, the molecular mechanisms of transcriptional regulation underlying PHS remain largely unknown. Results In the current study, comparative transcriptome analyses were performed to characterize the similarities and differences between two rice varieties: PHS-sensitive Jiuxiangzhan (JXZ) and PHS-resistant Meixiangxinzhan (MXXZ). The physiological experimental results indicated that PHS causes a significant decrease in starch content and, in contrast, a significant increase in soluble sugar content and amylase activity. The extent of change in these physiological parameters in the sensitive variety JXZ was greater than that in the resistant variety MXXZ. A total of 9,602 DEGs were obtained from the transcriptome sequencing data, and 5,581 and 4,021 DEGs were identified in JXZ and MXXZ under high humidity conditions, respectively. The KEGG pathway enrichment analysis indicated that many DEGs under high humidity treatment were mainly linked to plant hormone signal transduction, carbon metabolism, starch and sucrose metabolism, and phenylpropanoid biosynthesis. Furthermore, the number of upregulated genes involved in these pathways was much higher in JXZ than in MXXZ, while the number of downregulated genes was higher in MXXZ than in JXZ. These results suggest that the physiological and biochemical processes of these pathways are more active in the PHS-sensitive JXZ than in the PHS-resistant MXXZ. Conclusion Based on these results, we inferred that PHS in rice results from altered phytohormone regulation, more active carbon metabolism and energy production, and enhanced phenylpropanoid biosynthesis. Our study provides a theoretical foundation for further elucidation of the complex regulatory mechanism of PHS in rice and the molecular breeding of PHS-resistant rice varieties.

Wheat pre-harvest sprouting (PHS) refers to the germination of seeds directly on the spike due to rainy weather before harvest, which often results in yield reduction, quality deterioration, and seed value loss. In this study, we reviewed the research progress in the quantitative trait loci (QTL) detection and gene excavation related to PHS resistance in wheat. Simultaneously, the identification and creation of germplasm resources and the breeding of wheat with PHS resistance were expounded in this study. Furthermore, we also discussed the prospect of molecular breeding during genetic improvement of PHS-resistant wheat. [ABSTRACT FROM AUTHOR]

Seed dormancy is an important agronomic trait under the control of complex genetic and environmental interactions, which have not been yet comprehensively understood. From the field screening of rice mutant library generated by a Ds transposable element, we identified a pre-harvest sprouting (PHS) mutant dor1. This mutant has a single insertion of Ds element at the second exon of OsDOR1 (LOC_Os03g20770), which encodes a novel seed-specific glycine-rich protein. This gene successfully complemented the PHS phenotype of dor1 mutant and its ectopic expression enhanced seed dormancy. Here, we demonstrated that OsDOR1 protein binds to the GA receptor protein, OsGID1 in rice protoplasts, and interrupts with the formation OsGID1-OsSLR1 complex in yeast cells. Co-expression of OsDOR1 with OsGID1 in rice protoplasts attenuated the GA-dependent degradation of OsSLR1, the key repressor of GA signaling. We showed the endogenous OsSLR1 protein level in the dor1 mutant seeds is significantly lower than that of wild type. The dor1 mutant featured a hypersensitive GA-response of α-amylase gene expression during seed germination. Based on these findings, we suggest that OsDOR1 is a novel negative player of GA signaling operated in the maintenance of seed dormancy. Our findings provide a novel source of PHS resistance. Key message: OsDOR1, the causal gene for the rice PHS mutant dor1, is a novel positive regulator of seed dormancy through interaction with the GID1-SLR1 complex and stabilization of the SLR1 protein in rice seeds. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) of rice (Oryza sativa L.) causes severe economic problems due to reduced grain quality and yield. Fine mapping was carried out to identify genes associated with PHS; the detected quantitative trait locus (QTL) was narrowed down to 50 Kbp using F3:4 populations, four polymorphic insertion and deletion (InDel) markers, and two cleaved amplified polymorphic sequence (CAPS) markers. In one region, five candidate genes were detected, and the SNP and InDel in each gene (Os01g0111400 and Os01g0111600) were confirmed to show the differences and resulting amino acid changes between parent plants. Based on haplotype, expression, and co-segregation analysis, the InDel in Os01g0111600 was confirmed to be associated with the PHS trait. The results of this study could be applied to improve the PHS tolerance of Japonica rice varieties, and they also improved our understanding of the genetic basis underlying PHS tolerance. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) is an environmentally induced phenomenon, which causes severe yield losses in urdbean under humid weather conditions. Concerning PHS, deployment of genotypic capacity for PHS tolerance would be a feasible approach, but has not been evaluated in urdbean. Therefore, a laboratory-based study was conducted to investigate the genotypic potential of PHS tolerance in urdbean and to understand the influence of various seed and pod physical and physiological traits on PHS. A panel of 140 diverse urdbean genotypes was tested for seed and pod morphological attributes, water imbibitions patterns, fresh seed germination, germination time, and physical dormancy or hard seededness for characterizing the trait PHS. A wider variation in PHS (3–94%) was observed within the genotypes and the trait hard seededness was found as the key determinant of PHS tolerance in urdbean. The genotypes with lower PHS (< 10%) had a mean hard seededness of 77%, while, the genotypes with higher PHS (> 70%) recorded a mean hard seededness of 7%. Results further demonstrated that the persistence of hard seededness is highly genotype specific and temporal in character, which was highest in the freshly harvested seeds and decline over the storage period. The correlation results indicated that seed weight, seed length, pod water imbibitions, seed water imbibitions, mean germination time, and fresh seed germination positively influenced PHS. The large-seeded genotypes (> 4 g 100 seeds−1) showed higher PHS than the small-seeded genotypes (< 3 g 100 seeds−1). The multivariate analysis results further confirmed the positive relationship of PHS with pod water imbibitions, fresh seed germination, and 100-seed weight. The PHS tolerant genotypes PLU 302, CN 35–15, and PLU 65, which recorded hard seededness of 70–88% after harvesting, and reduced to < 24% after 60 days could be used as potential donors for the improvement of urdbean. [ABSTRACT FROM AUTHOR]

Domestication and extensive selection in the development of modern, high-yielding commercial groundnut cultivars have resulted in the selection of an undesirable trait known as in situ germination, which is also referred to as the pre-harvest sprouting of seeds. This is particularly prevalent in regions where humid weather coincides with the harvest season. Delayed harvesting and pre-sprouting can cause production losses and increase the chances of aflatoxin contamination, thereby impeding the quality and kernel yield. Breeding early maturing groundnut cultivars with 2–3 weeks of fresh seed dormancy, particularly in Spanish-type cultivars, enhances the sustainability of agriculture. In this context, we conducted a comprehensive evaluation of a groundnut mini-core collection, a major resource for genetic diversity, for fresh seed dormancy using an in vitro germination assay for two seasons, viz., rainy 2022 and post-rainy 2022–2023 at ICRISAT (Hyderabad). To enhance the effectiveness and accuracy of traditional breeding methods via the use of markers for marker-assisted selection, we performed molecular screening of the mini-core accessions using two allele-specific markers. The GMFSD1 marker was successfully validated by effectively differentiating dormant and non-dormant genotypes. By employing phenotypic and marker data, we identified a set of accessions, viz., ICG 5827 (Virginia Runner), ICG 11457 (Virginia Runner), ICG 7000 (Virginia Bunch), and ICG 11322 (Virginia Bunch) of sub spp. hypogaea var. hypogaea and ICG 9809 (Spanish Bunch) of sub spp. fastigiata var. vulgaris that exhibited a fresh seed dormancy period ranging from 2 to 3 weeks. These identified accessions hold potential as donors in breeding programs that are designed to address the groundnut production needs in various cropping systems across different countries. The validated marker, particularly GMFSD1, demonstrated considerable potential for facilitating faster breeding of groundnut cultivars with the desired dormancy using marker-assisted selection. This research provides a foundation to expediting groundnut breeding programs and offers opportunities to mitigate pre-harvest sprouting, ultimately improving seed quality and productivity in groundnut-producing regions.

Pre-harvest sprouting (PHS) is a condition triggered by environmental factors, particularly prevalent in humid conditions, leading to substantial yield losses in black gram. While the potential for genotypic PHS tolerance exists, it has not been thoroughly assessed in black gram. Hence, the present study aimed to delve into the genetic variation for PHS tolerance in diverse black gram (Vigna mungo (L.) Hepper) germplasm, and also to comprehend the impact of various physical and physiological traits on PHS. A diverse set of 112 black gram accessions collected across the phytogeographical zones of India were examined for their seed and pod characteristics. Water absorption by pods and seeds and fresh-seed germination was calculated by following the standard procedure given by the International Seed Testing Association. The alpha-amylase activity was measured on dry seeds (0 h), 24 h, 48 h, and 72 h after germination of each accession, using a UV-VIS spectrophotometer, and hard-seededness was measured using a texture analyzer machine. The results showed a wide range in PHS tolerance and FSG, and 13 accessions were found to be PHS-tolerant (PHS value < 10%). An indicator of PHS, seed germination in a pod, ranged from 2.75% in IC485641 (highly tolerant to PHS) to 95.85% in IC530501 (highly susceptible to PHS). Correlation and multivariate analysis revealed that PHS was positively correlated with water imbibition by pod and seed, fresh-seed germination and alpha-amylase activity. PHS-tolerant accessions showed a slow increase in alpha-amylase activity, in contrast to PHS-susceptible accessions. The utilization of alpha-amylase activity as a biochemical marker has the potential for evaluating PHS tolerance across various black gram accessions. The identified PHS-tolerant accessions can be used as donors in crop improvement programs aimed at developing PHS-tolerant black gram varieties.

Pre-harvest sprouting (PHS), the germination of seeds on the plant prior to harvest, poses significant challenges to agriculture. It not only reduces seed and grain yield, but also impairs the commodity quality of the fruit, ultimately affecting the success of the subsequent crop cycle. A deeper understanding of PHS is essential for guiding future breeding strategies, mitigating its impact on seed production rates and the commercial quality of fruits. PHS is a complex phenomenon influenced by genetic, physiological, and environmental factors. Many of these factors exert their influence on PHS through the intricate regulation of plant hormones responsible for seed germination. While numerous genes related to PHS have been identified in food crops, the study of PHS in vegetable crops is still in its early stages. This review delves into the regulatory elements, functional genes, and recent research developments related to PHS in vegetable crops. Meanwhile, this paper presents a novel understanding of PHS, aiming to serve as a reference for the study of this trait in vegetable crops.

Abstract Background Wheat (Triticum aestivum L.) is an important cereal crop. Increasing grain yield for wheat is always a priority. Due to the complex genome of hexaploid wheat with 21 chromosomes, it is difficult to identify underlying genes by traditional genetic approach. The combination of genetics and omics analysis has displayed the powerful capability to identify candidate genes for major quantitative trait loci (QTLs), but such studies have rarely been carried out in wheat. In this study, candidate genes related to yield were predicted by a combined use of linkage mapping and weighted gene co-expression network analysis (WGCNA) in a recombinant inbred line population. Results QTL mapping was performed for plant height (PH), spike length (SL) and seed traits. A total of 68 QTLs were identified for them, among which, 12 QTLs were stably identified across different environments. Using RNA sequencing, we scanned the 99,168 genes expression patterns of the whole spike for the recombinant inbred line population. By the combined use of QTL mapping and WGCNA, 29, 47, 20, 26, 54, 46 and 22 candidate genes were predicted for PH, SL, kernel length (KL), kernel width, thousand kernel weight, seed dormancy, and seed vigor, respectively. Candidate genes for different traits had distinct preferences. The known PH regulation genes Rht-B and Rht-D, and the known seed dormancy regulation genes TaMFT can be selected as candidate gene. Moreover, further experiment revealed that there was a SL regulatory QTL located in an interval of about 7 Mbp on chromosome 7A, named TaSL1, which also involved in the regulation of KL. Conclusions A combination of QTL mapping and WGCNA was applied to predicted wheat candidate genes for PH, SL and seed traits. This strategy will facilitate the identification of candidate genes for related QTLs in wheat. In addition, the QTL TaSL1 that had multi-effect regulation of KL and SL was identified, which can be used for wheat improvement. These results provided valuable molecular marker and gene information for fine mapping and cloning of the yield-related trait loci in the future.

Abstract Background Pre-harvest sprouting (PHS) refers to a phenomenon, in which the physiologically mature seeds are germinated on the spike before or during the harvesting practice owing to high humidity or prolonged period of rainfall. Pre-harvest sprouting (PHS) remarkably decreases seed quality and yield in wheat; hence it is imperative to uncover genomic regions responsible for PHS tolerance to be used in wheat breeding. A genome-wide association study (GWAS) was carried out using 298 bread wheat landraces and varieties from Iran to dissect the genomic regions of PHS tolerance in a well-irrigated environment. Three different approaches (RRBLUP, GBLUP and BRR) were followed to estimate prediction accuracies in wheat genomic selection. Results Genomes B, A, and D harbored the largest number of significant marker pairs (MPs) in both landraces (427,017, 328,006, 92,702 MPs) and varieties (370,359, 266,708, 63,924 MPs), respectively. However, the LD levels were found the opposite, i.e., genomes D, A, and B have the highest LD, respectively. Association mapping by using GLM and MLM models resulted in 572 and 598 marker-trait associations (MTAs) for imputed SNPs (− log10 P > 3), respectively. Gene ontology exhibited that the pleitropic MPs located on 1A control seed color, α-Amy activity, and PHS. RRBLUP model indicated genetic effects better than GBLUP and BRR, offering a favorable tool for wheat genomic selection. Conclusions Gene ontology exhibited that the pleitropic MPs located on 1A can control seed color, α-Amy activity, and PHS. The verified markers in the current work can provide an opportunity to clone the underlying QTLs/genes, fine mapping, and genome-assisted selection.Our observations uncovered key MTAs related to seed color, α-Amy activity, and PHS that can be exploited in the genome-mediated development of novel varieties in wheat.

Pre-harvest sprouting (PHS) of wheat reduces grain yield and quality, and it is strongly affected by seed dormancy. Therefore, identification of quantitative trait loci (QTL) for seed dormancy is essential for PHS resistance breeding. A doubled haploid (DH) population, consisting of 174 lines from the cross between Yangmai16 (YM16) and Zhongmai895 (ZM895) was used to detect QTLs for seed dormancy and grain color. For seed dormancy, a total of seven QTLs were detected on chromosomes 2A, 3A, 3D, 4D, 5B and 5D over four environments, among which Qdor.hzau-3A, Qdor.hzau-3D.1 and Qdor.hzau-3D.2 were stably detected in more than two environments. For grain color, only two QTLs, Qgc.hzau-3A and Qgc.hzau-3D were detected on chromosomes 3A and 3D, which physically overlapped with Qdor.hzau-3A and Qdor.hzau-3D.1, respectively. Qdor.hzau-3D.2 has never been reported elsewhere and is probably a novel locus with allelic effect of seed dormancy contributed by weakly dormant parent ZM895, and a KASP marker was developed and validated in a wheat natural population. This study provides new information on the genetic dissection of seed dormancy, which may aid in further improvement for marker-assisted wheat breeding for PHS resistance. [ABSTRACT FROM AUTHOR]

Introduction: Pre-harvest Sprouting (PHS) seriously affects wheat quality and yield. However, to date there have been limited reports. It is of great urgency to breed resistance varieties via quantitative trait nucleotides (QTNs) or genes for PHS resistance in white-grained wheat. Methods: 629 Chinese wheat varieties, including 373 local wheat varieties from 70 years ago and 256 improved wheat varieties were phenotyped for spike sprouting (SS) in two environments and genotyped by wheat 660K microarray. These phenotypes were used to associate with 314,548 SNP markers for identifying QTNs for PHS resistance using several multi-locus genome-wide association study (GWAS) methods. Their candidate genes were verified by RNA-seq, and the validated candidate genes were further exploited in wheat breeding. Results: As a result, variation coefficients of 50% and 47% for PHS in 629 wheat varieties, respectively, in 2020-2021 and 2021-2022 indicated large phenotypic variation, in particular, 38 white grain varieties appeared at least medium resistance, such as Baipimai, Fengchan 3, and Jimai 20. In GWAS, 22 significant QTNs, with the sizes of 0.06% - 38.11%, for PHS resistance were stably identified by multiple multilocus methods in two environments, e.g., AX-95124645 (chr3D:571.35Mb), with the sizes of 36.390% and 45.850% in 2020-2021 and 2021-2022, respectively, was detected by several multi-locus methods in two environments. As compared with previous studies, the AX-95124645 was used to develop Kompetitive Allele-Specific PCR marker QSS.TAF9-3D (chr3D:569.17Mb-573.55Mb) for the first time, especially, it is available in white-grain wheat varieties. Around this locus, nine genes were significantly differentially expressed, and two of them (TraesCS3D01G466100 and TraesCS3D01G468500) were found by GO annotation to be related to PHS resistance and determined as candidate genes. Discussion: The QTN and two new candidate genes related to PHS resistance were identified in this study. The QTN can be used to effectively identify the PHS resistance materials, especially, all the white-grained varieties with QSS.TAF9-3DTT haplotype are resistant to spike sprouting. Thus, this study provides candidate genes, materials, and methodological basis for breeding wheat PHS resistance in the future. [ABSTRACT FROM AUTHOR]

Introduction: Seed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusive Seed dormancy (SD) significantly decreases under high temperature (HT) environment during seed maturation, resulting in pre-harvest sprouting (PHS) damage under prolonged rainfall and wet weather during wheat harvest. However, the molecular mechanism underlying HT-mediated SD remains elusive. Methods: Here, the wheat landrace ‘Waitoubai’ with strong SD and PHS resistance was treated with HT from 21 to 35 days post anthesis (DPA). Then, the seeds under HT and normal temperature (NT) environments were collected at 21 DPA, 28 DPA, and 35 DPA and subjected to whole-transcriptome sequencing. Results: The phenotypic data showed that the seed germination percentage significantly increased, whereas SD decreased after HT treatment compared with NT, consistent with the results of previous studies. In total, 5128 mRNAs, 136 microRNAs (miRNAs), 273 long non-coding RNAs (lncRNAs), and 21 circularRNAs were found to be responsive to HT, and some of them were further verified through qRT-PCR. In particular, the known gibberellin (GA) biosynthesis gene TaGA20ox1 (TraesCS3D02G393900) was proved to be involved in HT-mediated dormancy by using the EMS-mutagenized wheat cultivar Jimai 22. Similarly, a novel gene TaCDPK21 (TraesCS7A02G267000) involved in the calcium signaling pathway was validated to be associated with HT-mediated dormancy by using the EMS mutant. Moreover, TaCDPK21 overexpression in Arabidopsis and functional complementarity tests supported the negative role of TaCDPK21 in SD. We also constructed a co-expression regulatory network based on differentially expressed mRNAs, miRNAs, and lncRNAs and found that a novel miR27319 was located at a key node of this regulatory network. Subsequently, using Arabidopsis and rice lines overexpressing miR27319 precursor or lacking miR27319 expression, we validated the positive role of miR27319 in SD and further preliminarily dissected the molecular mechanism of miR27319 underlying SD regulation through phytohormone abscisic acid and GA biosynthesis, catabolism, and signaling pathways. Discussion: These findings not only broaden our understanding of the complex regulatory network of HT-mediated dormancy but also provide new gene resources for improving wheat PHS resistance to minimize PHS damage by using the molecular pyramiding approach. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting is a frequent problem for wheat culture that can be simulated by laboratory-based germination. Despite reducing baking properties, wheat sprouting has been shown to increase the bioavailability of some nutrients. It was investigated whether wheat cultivars bearing distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in terms of the changes in phytochemical compounds during germination. Using LC-Q-TOF-MS, higher contents of benzoxazinoids and flavonoids were found in the hard cultivar than in the soft one. Free phytochemicals, mainly benzoxazinoids, increased during germination in both cultivars. Before germination, soft and hard cultivars had a similar profile of matrix-bound phytochemicals, but during germination, these compounds have been shown to decrease only in the hard-texture cultivar, due to decreased levels of phenolic acids (trans-ferulic acid) and flavonoids (apigenin) that were bound to the cell wall through ester-type bonds. These findings confirm the hypothesis that hard and soft wheat cultivars have distinct behavior during germination concerning the changes in phytochemical compounds, namely the matrix-bound compounds. In addition, germination has been shown to remarkably increase the content of benzoxazinoids and the antioxidant capacity, which could bring a health-beneficial appeal for pre-harvested sprouted grains. [ABSTRACT FROM AUTHOR]

The review is devoted to pre-harvest sprouting (PHS) in soft wheat (Triticum aestivum L.) as one of the main problems faced by specialists in the field of genetics and selection of grain crops. Pre-harvest sprouting leads to a decrease in yields and economic losses. In the present work, the internal and external factors which influence PHS grain crops, as well as their interrelation, have been described. The characteristics of efficiency and features of the use of physiological biochemical and molecular genetic methods to evaluate the pre-harvest sprouting resistance of soft wheat grain are given. [ABSTRACT FROM AUTHOR]

Vivipary also known as the precocious germination of seeds while still attached to the mother plant or fruit, it's a relatively common phenomenon in angiosperms. However, the proliferating seedlings though interesting to look at, deter customers from eating the fruits. Similarly, vivipary is an adverse phenomenon for the agroindustry because of the lowest quality and palatability of fruits as well as lower seed set and viability. This paper highlights the taxonomic occurrence of vivipary in cereal and crop plants and the detrimental effects of this phenomenon in agricultural crops. According to literature sources, there are 38 fruit crops in which vivipary has been reported. The families Cucurbitaceae, Poaceae, Rutaceae, and Solanaceae include the fruits with the highest incidence of vivipary in the markets. [ABSTRACT FROM AUTHOR]