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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]

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]

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]

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]

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]

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]

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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]

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]

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 (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.caas3A 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 PHSrelated 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_AX109605367and 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. [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]

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]

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]

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]

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]

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]

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. [ABSTRACT FROM AUTHOR]

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Pre -harvest sprouting (PHS) is an important problem in cereal production reducing yield and grain quality. After decades of improvement, triticale remains particularly susceptible to PHS but no resistance genes or QTLs were identified so far in this species. As wheat shares the A and B genomes with triticale, wheat PHS resistance genes can be introgressed into triticale genome by recombination after interspecific crosses. In this project, three PHS resistance genes have been transferred from wheat to triticale by marker-assisted interspecific crosses, followed by four backcrosses. The gene TaPHS1 from the 3AS chromosome of cultivar Zenkoujikomugi (Zen) and the TaMKK3 and TaQsd1, respectively located on the 4AL and 5BL chromosomes derived both from cultivar Aus1408, were pyramided in the triticale cultivar Cosinus. Only the TaPHS1 gene increases consistently the PHS resistance in triticale. The lack of efficacy of the other two genes, especially TaQsd1, could be the result of an imperfect linkage between the marker and the gene of interest. The introduction of PHS resistance genes did not alter agronomic nor disease resistance performances of triticale. This approach leads to two new, agronomically performant and PHS-resistant triticale cultivars. Today, two breeding triticale lines are ready to enter the official registration process. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

Pre‐harvest sprouting (PHS), which reduces grain yield and quality, is controlled by seed dormancy genes. Because few dormancy‐related genes have been cloned, the genetic basis of seed dormancy in rice (Oryza sativa L.) remains unclear. Here, we performed a genome‐wide association study and linkage mapping to dissect the genetic basis of seed dormancy in rice. Our findings suggest that Seed Dormancy4 (Sdr4), a central modulator of seed dormancy, integrates the abscisic acid and gibberellic acid signaling pathways at the transcriptional level. Haplotype analysis revealed that three Sdr4 alleles in rice cultivars already existed in ancestral Oryza rufipogon accessions. Furthermore, like the semi‐dwarf 1 (SD1) and Rc loci, Sdr4 underwent selection during the domestication and improvement of Asian cultivated rice. The distribution frequency of the Sdr4‐n allele in different locations in Asia is negatively associated with local annual temperature and precipitation. Finally, we developed functional molecular markers for Sdr4, SD1, and Rc for use in molecular breeding. Our results provide clues about the molecular basis of Sdr4‐regulated seed dormancy. Moreover, these findings provide guidance for utilizing the favorable alleles of Sdr4 and Rc to synergistically boost PHS resistance, yield, and quality in modern rice varieties. [ABSTRACT FROM AUTHOR]

CRISPR/Cas9-mediated restoration of Tamyb10 to create pre-harvest sprouting-resistant red wheat (a) Gene structures of Tamyb10-B1b in red wheat and Tamyb10-B1a in white wheat. Keywords: CRISPR/Cas9; functional recovery; Tamyb10; pre-harvest sprouting; red wheat EN CRISPR/Cas9 functional recovery Tamyb10 pre-harvest sprouting red wheat 665 667 3 03/28/23 20230401 NES 230401 Wheat pre-harvest sprouting (PHS) reduces yield and grain quality and occurs in almost every wheat-growing region around the world (Vetch I et al i ., [4]). [Extracted from the article]

Pre-harvest sprouting is a concern in malting barley (Hordeum vulgare L.) in areas with a high amount of rainfall, as it decreases grain yield and malt quality. Thus, we investigated the changes in initial germination and the rate of dormancy loss in seeds of 20 promising barley genotypes at seven locations for two years (2013–2015) in Iran. Initial germination ranged between 5.23% (genotype "Teran 78/1-BC-80,411") and 38.45% (genotype "CIRU/M111") at the maturity. In several genotypes, there were negative associations between initial germination and the average temperature in March, April and May. The rate of dormancy loss and precipitation were negatively correlated in 14 genotypes in March. Thus, a hot and dry condition during seed development can decrease initial germination but can increase the rate of dormancy loss in barley. A genotype with high initial germination is suitable for cultivation in regions with a dry climate during grain development, and a genotype with a high rate of dormancy loss is appropriate in a climate with high rainfall and relative humidity. In conclusion, breeding programs must link dormancy intensity of target barley and environmental conditions (air temperature and humidity) that the crop will experience. [ABSTRACT FROM AUTHOR]

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Background: Wheat (Triticum aestivum L.) ABA insensitive five (ABI5) binding protein gene (TaAFP) is a homologue of the ABI5 binding protein (AFP) gene in Arabidopsis thaliana. It is well documented that AtAFP is a negative regulator of ABA signaling that regulates embryo germination and seed dormancy. TaABI5 was earlier shown to be expressed specifically in seed and its transcript accumulated during wheat grain maturation and acquisition of dormancy. It plays an important role in seed dormancy. In a previous study, we identified two allelic variants TaAFP-B1a and TaAFP-B1b of TaAFP on chromosome arm 2BS in common wheat, designated as, respectively. Sequence analysis revealed a 4 bp insertion in the promoter of TaAFP-B1a compared with TaAFP-B1b that affected mRNA transcription level, mRNA stability, GUS and tdTomatoER translation level, and GUS activity determining seed dormancy. Results: The transcription and translation levels of TaAFP-B were significantly reduced in TaAFP-Ba and TaAFP-Ba-GFP transgenic plants compared with TaAFP-Bb and TaAFP-Bb-GFP. The average GI (germination index) values of TaAFP-Ba and TaAFP-Ba-GFP were significantly lower than those of TaAFP-Bb and TaAFP-Bb-GFP in T1 and T2 transgenic rice seeds, whereas mature TaAFP-Ba and TaAFP-Ba-GFP transgenic seeds exhibited increased ABA sensitivity and content of endogenous ABA compared with TaAFP-Bb and TaAFP-Bb-GFP. Conclusion: The 4 bp insertion in the promoter of TaAFP-Ba decreased transcript abundance and translation level in transgenic rice. This insertion increased sensitivity to ABA and content of endogenous ABA in mature seeds, leading to a higher seed dormancy and pre-harvest sprouting tolerance in transgenic rice. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting is one of the most serious problems in rice production. Sensitive pre-harvest sprouting causes low seed quality and losses before harvesting. Seed dormancy is one of the most important traits relative to pre-harvest sprouting. In this study, the common wild rice, Oryza rufipogon W630 (strong seed dormancy) was used as a donor to improve the pre-harvest sprouting resistance of O. sativa Indica IR36 (popular cultivar in Asia). Thereafter, 170 backcross recombinant inbred lines (BRILs) at the BC2F8 generation were produced by the single seed descendant method. Their degree of dormancy was assessed and genotype was analyzed using 180 polymorphic SSR markers covering entire chromosomes. Finally, a QTL analysis was conducted by composite interval mapping to identify putative QTLs of seed dormancy and the wild allele effects to the background of typical rice cultivar IR36. Thus, two of 170 BRILs showed stronger seed dormancy compared to recurrent parent IR36. In addition, two putative QTLs for seed dormancy at chromosome 2 and 7 were also found in this population through composite interval mapping. These results indicated the stronger dormancy trait of two BRILs derived from wild rice Oryza rufipogon W630; this trait was also controlled by genetic factors. [ABSTRACT FROM AUTHOR]

Summary: High humidity during harvest season often causes pre‐harvest sprouting in barley (Hordeum vulgare). Prolonged grain dormancy prevents pre‐harvest sprouting; however, extended dormancy can interfere with malt production and uniform germination upon sowing. In this study, we used Cas9‐induced targeted mutagenesis to create single and double mutants in QTL FOR SEED DORMANCY 1 (Qsd1) and Qsd2 in the same genetic background. We performed germination assays in independent qsd1 and qsd2 single mutants, as well as in two double mutants, which revealed a strong repression of germination in the mutants. These results demonstrated that normal early grain germination requires both Qsd1 and Qsd2 function. However, germination of qsd1 was promoted by treatment with 3% hydrogen peroxide, supporting the notion that the mutants exhibit delayed germination. Likewise, exposure to cold temperatures largely alleviated the block of germination in the single and double mutants. Notably, qsd1 mutants partially suppress the long dormancy phenotype of qsd2, while qsd2 mutant grains failed to germinate in the light, but not in the dark. Consistent with the delay in germination, abscisic acid accumulated in all mutants relative to the wild type, but abscisic acid levels cannot maintain long‐term dormancy and only delay germination. Elucidation of mutant allele interactions, such as those shown in this study, are important for fine‐tuning traits that will lead to the design of grain dormancy through combinations of mutant alleles. Thus, these mutants will provide the necessary germplasm to study grain dormancy and germination in barley. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS) is a common threat to cereal crops in which the grain maturation phase takes place under rainy, moist conditions. Susceptibility to PHS is higher in sorghum genotypes displaying low levels of seed dormancy before harvest maturity. Other attributes such as glume or panicle morphology may also affect susceptibility to PHS. Breeding for resistance to PHS in grain sorghum requires the identification of grain physiological and morphological attributes affecting this trait, and a protocol for phenotyping and rating genotypes according to their susceptibility to PHS. In this work, we tested germination under laboratory conditions using detached grains and intact panicles for a panel of 20 sorghum genotypes including 11 parental lines, 6 hybrids and 3 reference inbred lines with contrasting PHS response. Records for natural sprouting in the field for these genotypes were also included in the analysis. Multivariate analyses of germination data allowed separation of genotypes into two major categories (resistant and susceptible to PHS). Laboratory germination data correlated significantly with PHS in the field. In most genotypes, the glumes had a significant, inhibitory effect on germination. The low levels of grain dormancy were observed among high tannin backgrounds, and vice versa, indicating that a pigmented testa alone does not provide resistance to PHS. Altogether, the phenotyping protocol allowed the classification of sorghum genotypes according to their susceptibility to PHS and the identification of different attributes useful for breeding for PHS resistance in this crop. [ABSTRACT FROM AUTHOR]

Copyright of COMU Journal of Agriculture Faculty / ÇOMÜ Ziraat Fakültesi Dergisi is the property of Canakkale Onsekiz Mart University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: Pre‐harvest sprouting (PHS), the germination of grain before harvest, is a serious problem resulting in wheat yield and quality losses.Here, we mapped the PHS resistance gene PHS‐3D from synthetic hexaploid wheat to a 2.4 Mb presence–absence variation (PAV) region and found that its resistance effect was attributed to the pleiotropic Myb10‐D by integrated omics and functional analyses.Three haplotypes were detected in this PAV region among 262 worldwide wheat lines and 16 Aegilops tauschii, and the germination percentages of wheat lines containing Myb10‐D was approximately 40% lower than that of the other lines. Transcriptome and metabolome profiling indicated that Myb10‐D affected the transcription of genes in both the flavonoid and abscisic acid (ABA) biosynthesis pathways, which resulted in increases in flavonoids and ABA in transgenic wheat lines. Myb10‐D activates 9‐cis‐epoxycarotenoid dioxygenase (NCED) by biding the secondary wall MYB‐responsive element (SMRE) to promote ABA biosynthesis in early wheat seed development stages.We revealed that the newly discovered function of Myb10‐D confers PHS resistance by enhancing ABA biosynthesis to delay germination in wheat. The PAV harboring Myb10‐D associated with grain color and PHS will be useful for understanding and selecting white grained PHS resistant wheat cultivars. [ABSTRACT FROM AUTHOR]

Background: Cucumber (Cucumis sativus L.) is cultivated worldwide, and it is essential to produce enough high-quality seeds to meet demand. Pre-harvest sprouting (PHS) in cucumber is a critical problem and causes serious damage to seed production and quality. Nevertheless, the genetic basis and molecular mechanisms underlying cucumber PHS remain unclear. QTL-seq is an efficient approach for rapid quantitative trait loci (QTL) identification that simultaneously takes advantage of bulked-segregant analysis (BSA) and whole-genome resequencing. In the present research, QTL-seq analysis was performed to identify QTLs associated with PHS in cucumber using an F2 segregating population. Results: Two QTLs that spanned 7.3 Mb on Chromosome 4 and 0.15 Mb on Chromosome 5 were identified by QTL-seq and named qPHS4.1 and qPHS5.1, respectively. Subsequently, SNP and InDel markers selected from the candidate regions were used to refine the intervals using the extended F2 populations grown in the 2016 and 2017 seasons. Finally, qPHS4.1 was narrowed to 0.53 Mb on chromosome 4 flanked by the markers SNP-16 and SNP-24 and was found to explain 19–22% of the phenotypic variation in cucumber PHS. These results reveal that qPHS4.1 is a major-effect QTL associated with PHS in cucumber. Based on gene annotations and qRT-PCR expression analyses, Csa4G622760 and Csa4G622800 were proposed as the candidate genes. Conclusions: These results provide novel insights into the genetic mechanism controlling PHS in cucumber and highlight the potential for marker-assisted selection of PHS resistance breeding. [ABSTRACT FROM AUTHOR]

With the growth of the global population and the increasing frequency of natural disasters, crop yields must be steadily increased to enhance human adaptability to risks. Pre-harvest sprouting (PHS), a term mainly used to describe the phenomenon in which grains germinate on the mother plant directly before harvest, is a serious global problem for agricultural production. After domestication, the dormancy level of cultivated crops was generally lower than that of their wild ancestors. Although the shortened dormancy period likely improved the industrial performance of cereals such as wheat, barley, rice, and maize, the excessive germination rate has caused frequent PHS in areas with higher rainfall, resulting in great economic losses. Here, we systematically review the causes of PHS and its consequences, the major indicators and methods for PHS assessment, and emphasize the biological significance of PHS in crop production. Wheat quantitative trait loci functioning in the control of PHS are also comprehensively summarized in a meta-analysis. Finally, we use Arabidopsis as a model plant to develop more complete PHS regulatory networks for wheat. The integration of this information is conducive to the development of custom-made cultivated lines suitable for different demands and regions, and is of great significance for improving crop yields and economic benefits. [ABSTRACT FROM AUTHOR]

Background: Pre-harvest sprouting (PHS) in wheat can cause severe damage to both grain yield and quality. Resistance to PHS is a quantitative trait controlled by many genes located across all 21 wheat chromosomes. The study targeted a large-effect quantitative trait locus (QTL) QPhs.ccsu-3A.1 for PHS resistance using several sets previously developed near-isogenic lines (NILs). Two pairs of NILs with highly significant phenotypic differences between the isolines were examined by RNA sequencing for their transcriptomic profiles on developing seeds at 15, 25 and 35 days after pollination (DAP) to identify candidate genes underlying the QTL and elucidate gene effects on PHS resistance. At each DAP, differentially expressed genes (DEGs) between the isolines were investigated. Results: Gene ontology and KEGG pathway enrichment analyses of key DEGs suggested that six candidate genes underlie QPhs.ccsu-3A.1 responsible for PHS resistance in wheat. Candidate gene expression was further validated by quantitative RT-PCR. Within the targeted QTL interval, 16 genetic variants including five single nucleotide polymorphisms (SNPs) and 11 indels showed consistent polymorphism between resistant and susceptible isolines. Conclusions: The targeted QTL is confirmed to harbor core genes related to hormone signaling pathways that can be exploited as a key genomic region for marker-assisted selection. The candidate genes and SNP/indel markers detected in this study are valuable resources for understanding the mechanism of PHS resistance and for marker-assisted breeding of the trait in wheat. [ABSTRACT FROM AUTHOR]

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Pre-harvest sprouting (PHS) leads to serious economic losses because of reductions in yield and quality. To analyze the quantitative trait loci (QTLs) for PHS resistance in japonica rice, PHS rates on panicles were measured in 160 recombinant inbred lines (RILs) derived from a cross between the temperate japonica varieties Odae (PHS resistant) and Unbong40 (PHS susceptible) under two different environmental conditions—field (summer) and greenhouse (winter) environments. Genome re-sequencing of the parental varieties detected 266,773 DNA polymorphisms including 248,255 single nucleotide polymorphisms and 18,518 insertions/deletions. We constructed a genetic map comprising 239 kompetitive allele-specific PCR and 49 cleaved amplified polymorphic sequence markers. In the field environment, two major QTLs, qPHS-3FD and qPHS-11FD, were identified on chromosomes 3 and 11, respectively, whereas three major QTLs, qPHS-3GH, qPHS-4GH, and qPHS-11GH, were identified on chromosomes 3, 4, and 11, respectively, in the greenhouse environment. qPHS-11GH and qPHS-11FD had similar locations on chromosome 11, suggesting the existence of a gene conferring stable PHS resistance effects under different environmental conditions. The QTLs identified in this study can be used to improve the PHS resistance of japonica varieties, and they may improve our understanding of the genetic basis of PHS resistance. [ABSTRACT FROM AUTHOR]