Physical dormancy(PY) commonly present in the seeds of higher plants is believed to be responsible for the germination failure by impermeable seed coat in hard seeds of legume species, instead of physiological dormanc...Physical dormancy(PY) commonly present in the seeds of higher plants is believed to be responsible for the germination failure by impermeable seed coat in hard seeds of legume species, instead of physiological dormancy(PD). In this study, a non-destructive approach involving multispectral imaging was used to successfully identify hard seeds from non-hard seeds in Medicago sativa, with accuracy as high as96.8%–99.0%. We further adopted multiple-omics strategies to investigate the differences of physiology,metabolomics, methylomics, and transcriptomics in alfalfa hard seeds, with non-hard seeds as control.The hard seeds showed dramatically increased antioxidants and 125 metabolites of significant differences in non-targeted metabolomics analysis, which are enriched in the biosynthesis pathways of flavonoids, lipids and hormones, especially with significantly higher ABA, a hormone known to induce dormancy. In our transcriptomics results, the enrichment pathway of “response to abscisic acid” of differential expressed genes(DEG) supported the key role of ABA in metabolomics results. The methylome analysis identified 54,899, 46,216 and 54,452 differential methylation regions for contexts of CpG, CHG and CHH, and 344 DEGs might be regulated by hypermethylation and hypomethylation of promoter and exon regions, including four ABA-and JA-responsive genes. Among 8% hard seeds in seed lots,24.5% still did not germinate after scarifying seed coat, and were named as non-PY hard seeds.Compared to hard seeds, significantly higher contents of ABA/IAA and ABA/JA were identified in nonPY hard seeds, which indicated the potential presence of PD. In summary, the significantly changed metabolites, gene expressions, and methylations all suggested involvement of ABA responses in hard seeds, and germination failure of alfalfa hard seeds was caused by combinational dormancy(PY + PD),rather than PY alone.展开更多
Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on...Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30℃, and alternating temperature 15-25, 20-30, 15-30, and 20-35℃ under either an 8h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO3 solution to saturate the seedbed, and prechilling for 7 d at 7℃ and mechanical scarification by cutting. The results showed that alternating temperature at 20-30℃ with 8 h photoperiod and 16 h darkness was optimum for G. uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.展开更多
Seeds play a central role in the life cycle of plants. Seed hardness in pomegranates is of economic relevance, yet scarcely studied and poorly understood in China. In this study, we compared the proteomic differences ...Seeds play a central role in the life cycle of plants. Seed hardness in pomegranates is of economic relevance, yet scarcely studied and poorly understood in China. In this study, we compared the proteomic differences between Zhongnonghong（soft-seeded） and Sanbai（hard-seeded） pomegranates. A total of 892 protein spots from both varieties were detected on two-dimensional electrophoresis gels（2-DE）; 76 spots showed greater than a 1.5-fold or less than a 0.66-fold difference（P〈0.05） in Zhongnonghong compared to Sanbai, of which 24 exhibited greater than a 2-fold change. Compared with Sanbai, Zhongnonghong possessed 14 up-regulated, and 10 down-regulated proteins. We identified and annotated 5 of these by using MALDI-TOF-TOF MS： pyruvate dehydrogenase（PDH） E1-β family protein（spot 4 609）; alanine aminotransferase 2-like（ALT2L）; mitochondrial glycine decarboxylase complex P-protein（spot 5 803）; phosphofructokinase B（Pfk B）-type family of carbohydrate kinase（spot 8 411）; and putative dna K-type molecular chaperone heat shock cognate protein 70（Hsc70）（spot 9 006）. Of these, 3 proteins（spots 4 609, 5 608, 5 803） were hypothesized to play a role in the formation of seed hardness. The other two proteins（spots 8 411, 9 006） were theorized to play a role in protecting the seeds from adverse stress during periods of fruit maturation. This study sets the foundation for further research on molecular mechanisms related to pomegranate seed hardness.展开更多
基金supported by the earmarked fund for CARS (CARS-34)National Key Research and Development Program of China (2022YFD1300804)the Key R&D Project of Sichuan Science and Technology Program(2023YFSY0012)。
文摘Physical dormancy(PY) commonly present in the seeds of higher plants is believed to be responsible for the germination failure by impermeable seed coat in hard seeds of legume species, instead of physiological dormancy(PD). In this study, a non-destructive approach involving multispectral imaging was used to successfully identify hard seeds from non-hard seeds in Medicago sativa, with accuracy as high as96.8%–99.0%. We further adopted multiple-omics strategies to investigate the differences of physiology,metabolomics, methylomics, and transcriptomics in alfalfa hard seeds, with non-hard seeds as control.The hard seeds showed dramatically increased antioxidants and 125 metabolites of significant differences in non-targeted metabolomics analysis, which are enriched in the biosynthesis pathways of flavonoids, lipids and hormones, especially with significantly higher ABA, a hormone known to induce dormancy. In our transcriptomics results, the enrichment pathway of “response to abscisic acid” of differential expressed genes(DEG) supported the key role of ABA in metabolomics results. The methylome analysis identified 54,899, 46,216 and 54,452 differential methylation regions for contexts of CpG, CHG and CHH, and 344 DEGs might be regulated by hypermethylation and hypomethylation of promoter and exon regions, including four ABA-and JA-responsive genes. Among 8% hard seeds in seed lots,24.5% still did not germinate after scarifying seed coat, and were named as non-PY hard seeds.Compared to hard seeds, significantly higher contents of ABA/IAA and ABA/JA were identified in nonPY hard seeds, which indicated the potential presence of PD. In summary, the significantly changed metabolites, gene expressions, and methylations all suggested involvement of ABA responses in hard seeds, and germination failure of alfalfa hard seeds was caused by combinational dormancy(PY + PD),rather than PY alone.
基金the National Key Tech-nologies R&D Program during the 11th Five-Year Plan period (2006BAD04A04-02)
文摘Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30℃, and alternating temperature 15-25, 20-30, 15-30, and 20-35℃ under either an 8h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO3 solution to saturate the seedbed, and prechilling for 7 d at 7℃ and mechanical scarification by cutting. The results showed that alternating temperature at 20-30℃ with 8 h photoperiod and 16 h darkness was optimum for G. uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.
基金funded by the Key Project of the National Science and Technology Basic Work of China(2012 FY110100)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2015-ZFRI)
文摘Seeds play a central role in the life cycle of plants. Seed hardness in pomegranates is of economic relevance, yet scarcely studied and poorly understood in China. In this study, we compared the proteomic differences between Zhongnonghong（soft-seeded） and Sanbai（hard-seeded） pomegranates. A total of 892 protein spots from both varieties were detected on two-dimensional electrophoresis gels（2-DE）; 76 spots showed greater than a 1.5-fold or less than a 0.66-fold difference（P〈0.05） in Zhongnonghong compared to Sanbai, of which 24 exhibited greater than a 2-fold change. Compared with Sanbai, Zhongnonghong possessed 14 up-regulated, and 10 down-regulated proteins. We identified and annotated 5 of these by using MALDI-TOF-TOF MS： pyruvate dehydrogenase（PDH） E1-β family protein（spot 4 609）; alanine aminotransferase 2-like（ALT2L）; mitochondrial glycine decarboxylase complex P-protein（spot 5 803）; phosphofructokinase B（Pfk B）-type family of carbohydrate kinase（spot 8 411）; and putative dna K-type molecular chaperone heat shock cognate protein 70（Hsc70）（spot 9 006）. Of these, 3 proteins（spots 4 609, 5 608, 5 803） were hypothesized to play a role in the formation of seed hardness. The other two proteins（spots 8 411, 9 006） were theorized to play a role in protecting the seeds from adverse stress during periods of fruit maturation. This study sets the foundation for further research on molecular mechanisms related to pomegranate seed hardness.
