Novel molecular and cell biological insights into function of rice α-amylase

Amylase ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Toshiaki Mitsui ◽  
Akihito Ochiai ◽  
Hiromoto Yamakawa ◽  
Kentaro Kaneko ◽  
Aya Kitajima-Koga ◽  
...  
Keyword(s):  
Intracellular Transport ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Binding Pocket ◽  
Rice Grain ◽  
Active Site Cleft ◽  
Key Factor ◽  
Organ Specific ◽  
Basic Biology ◽  
Grain Chalkiness

Abstract α-Amylases have been of interest in diverse fields for many years because of their importance in basic biology, agriculture, and industry. Starch hydrolysis in plants has been studied extensively in germinating cereal seeds. It is generally accepted that α-amylases are secretory enzymes with a pivotal role in the breakdown of starch reserves in the endosperm. Intriguingly, however, recent investigations reveal that some α-amylases degrade starch in the plastids of living cells. The recent solving of the crystal structure of rice AmyI-1 isoform shows that the binding pocket of starch binding site 1 situated outside of the active site cleft interacts with the substances other than oligosaccharides. These findings provided novel insights into structural and cell biological aspects of α-amylase functions in intracellular transport, organelle targeting, and organ-specific actions. Under global warming, abnormal high temperatures during rice grain filling increase grain chalkiness, resulting in yield loss. Intensive “omics” analyses of developing caryopses and mature grains grown under heat stress showed the downregulation of starch synthesis enzymes and the upregulation of α-amylases. Transgenic studies using ectopic overexpression and suppression of α-amylase revealed that α-amylase is a key factor in grain chalkiness. Here we discuss unique new functions of α-amylase in rice cells.

scholarly journals The Rho-family GTPase OsRac1 controls rice grain size and yield by regulating cell division

2019 ◽  
Vol 116 (32) ◽  
pp. 16121-16126 ◽  
Author(s):  
Ying Zhang ◽  
Yan Xiong ◽  
Renyi Liu ◽  
Hong-Wei Xue ◽  
Zhenbiao Yang
Keyword(s):  
Grain Size ◽  
Cell Division ◽  
Grain Yield ◽  
Molecular Mechanisms ◽  
Grain Filling ◽  
High Yield ◽  
Rice Grain ◽  
Rop Gtpase ◽  
Key Factor ◽  
Grain Width

Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.

scholarly journals Proteomic profiling reveals differentially expressed proteins associated with amylose accumulation during rice grain filling

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hengdong Zhang ◽  
Jiana Chen ◽  
Shuanglü Shan ◽  
Fangbo Cao ◽  
Guanghui Chen ◽  
...  
Keyword(s):  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Adenosine Diphosphate ◽  
Differentially Expressed ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Differentially Expressed Proteins ◽  
Proteomic Profiling ◽  
Rice Grains

Abstract Background Amylose accumulation in rice grains is controlled by genetic and environmental factors. Amylose content is a determinant factor of rice quality in terms of cooking and eating. Great variations in amylose content in indica rice cultivars have been observed. The current study was to identify differentially expressed proteins in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways and their relationships to amylose synthesis using two rice cultivars possess contrasting phenotypes in grain amylose content. Results Synthesis and accumulation of amylose in rice grains significantly affected the variations between rice cultivars in amylose contents. The high amylose content cultivar has three down-regulated differentially expressed proteins, i.e., LOC_Os01g62420.1, LOC_Os02g36600.1, and LOC_Os08g37380.2 in the glycolysis/gluconeogenesis pathway, which limit the glycolytic process and decrease the glucose-1-phosphate consumption. In the starch and sucrose metabolic pathway, an up-regulated protein, i.e., LOC_Os06g04200.1 and two down-regulated proteins, i.e., LOC_Os05g32710.1 and LOC_Os04g43360.1 were identified (Figure 4). Glucose-1-phosphate is one of the first substrates in starch synthesis and glycolysis that are catalyzed to form adenosine diphosphate glucose (ADPG), then the ADPG is catalyzed by granule-bound starch synthase I (GBSS I) to elongate amylose. Conclusions The results indicate that decreasing the consumption of glucose-1-phosphate in the glycolytic process is essential for the formation of ADPG and UDPG, which are substrates for amylose synthesis. In theory, amylose content in rice can be regulated by controlling the fate of glucose-1-phosphate.

scholarly journals Genome-wide Association Studies Reveal the Genetic Basis of Natural Ionomic Variation in Rice Grain Oryza Sativa Subsp. Indica

2021 ◽  
Author(s):  
Suong T. Cu ◽  
Nicholas Warnock ◽  
Julie Pasuquin ◽  
Michael Dingkuhn ◽  
James Stangoulis
Keyword(s):  
Genetic Basis ◽  
Agronomic Traits ◽  
Association Studies ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Genome Wide Association ◽  
Rice Grain ◽  
Genome Wide Association Studies ◽  
Potential Candidate ◽  
Genome Wide

Abstract This study presents a comprehensive study of the genetic bases controlling variation in the rice ionome employing genome-wide association studies (GWAS) with a diverse panel of indica accessions, each genotyped with 5.2 million markers. GWAS was performed for twelve elements including B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn and four agronomic traits including days to 50% flowering, grain yield, plant height and thousand grain weight (TGW). GWAS identified 128 loci associated with the grain elements and 57 associated with the agronomic traits. There were sixteen co-localization regions containing QTL for two or more traits. Fourteen grain element quantitative trait loci were stable across growing environments, which can be strong candidates to be used in marker-assisted selection to improve the concentrations of nutritive elements in rice grain. Potential candidate genes were revealed including OsNAS3 controlling the variation of Zn and Co concentrations. The effects of starch synthesis and grain filling on TGW and multiple grain elements were elucidated through the involvement of OsSUS1 and OsGSSB1 genes. Overall, our study provides crucial insights into the genetic basis of ionomic variations in rice and will facilitate improvement in breeding for trace mineral content.

scholarly journals A high-resolution genome-wide association study of the grain ionome and agronomic traits in rice Oryza sativa subsp. indica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suong T. Cu ◽  
Nicholas I. Warnock ◽  
Julie Pasuquin ◽  
Michael Dingkuhn ◽  
James Stangoulis
Keyword(s):  
Genome Wide Association Study ◽  
Agronomic Traits ◽  
Association Studies ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Genome Wide Association ◽  
Rice Grain ◽  
Genome Wide Association Studies ◽  
Potential Candidate ◽  
Genome Wide

AbstractThis study presents a comprehensive study of the genetic bases controlling variation in the rice ionome employing genome-wide association studies (GWAS) with a diverse panel of indica accessions, each genotyped with 5.2 million markers. GWAS was performed for twelve elements including B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn and four agronomic traits including days to 50% flowering, grain yield, plant height and thousand grain weight. GWAS identified 128 loci associated with the grain elements and 57 associated with the agronomic traits. There were sixteen co-localization regions containing QTL for two or more traits. Fourteen grain element quantitative trait loci were stable across growing environments, which can be strong candidates to be used in marker-assisted selection to improve the concentrations of nutritive elements in rice grain. Potential candidate genes were revealed including OsNAS3 linked to the locus that controls the variation of Zn and Co concentrations. The effects of starch synthesis and grain filling on multiple grain elements were elucidated through the likely involvement of OsSUS1 and OsGSSB1 genes. Overall, our study provides crucial insights into the genetic basis of ionomic variations in rice and will facilitate improvement in breeding for trace mineral content.

scholarly journals Embryo-Endosperm Interaction and Its Agronomic Relevance to Rice Quality

2020 ◽  
Vol 11 ◽  
Author(s):  
Lu An ◽  
Yang Tao ◽  
Hao Chen ◽  
Mingjie He ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Grain Filling ◽  
Endosperm Development ◽  
Rice Grain ◽  
Yield And Quality ◽  
Open Questions ◽  
Integrative View ◽  
Plant Sciences ◽  
Dominant Process ◽  
Grain Chalkiness

Embryo-endosperm interaction is the dominant process controlling grain filling, thus being crucial for yield and quality formation of the three most important cereals worldwide, rice, wheat, and maize. Fundamental science of functional genomics has uncovered several key genetic programs for embryo and endosperm development, but the interaction or communication between the two tissues is largely elusive. Further, the significance of this interaction for grain filling remains open. This review starts with the morphological and developmental aspects of rice grain, providing a spatial and temporal context. Then, it offers a comprehensive and integrative view of this intercompartmental interaction, focusing on (i) apoplastic nutrient flow from endosperm to the developing embryo, (ii) dependence of embryo development on endosperm, (iii) regulation of endosperm development by embryo, and (iv) bidirectional dialogues between embryo and endosperm. From perspective of embryo-endosperm interaction, the mechanisms underlying the complex quality traits are explored, with grain chalkiness as an example. The review ends with three open questions with scientific and agronomic importance that should be addressed in the future. Notably, current knowledge and future prospects of this hot research topic are reviewed from a viewpoint of crop physiology, which should be helpful for bridging the knowledge gap between the fundamental plant sciences and the practical technologies.

scholarly journals Proteomic profiling reveals differentially expressed proteins associated with amylose accumulation during rice grain filling

2020 ◽  
Author(s):  
Hengdong Zhang ◽  
Jiana Chen ◽  
Shuanglü Shah ◽  
Fangbo Cao ◽  
Guanghui Chen ◽  
...  
Keyword(s):  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Adenosine Diphosphate ◽  
Differentially Expressed ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Differentially Expressed Proteins ◽  
Proteomic Profiling ◽  
Rice Grains

Abstract Background Amylose accumulation in rice grains is controlled by genetic and environmental factors. Amylose content is a determinant factor of rice quality in terms of cooking and eating. Great variations in amylose content in indica rice cultivars have been observed. The current study was to identify differentially expressed proteins in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways and their relationships to amylose synthesis using two rice cultivars possess contrasting phenotypes in grain amylose content.Results Synthesis and accumulation of amylose in rice grains significantly affected the variations between rice cultivars in amylose contents. The high amylose content cultivar has three down-regulated differentially expressed proteins, i.e., LOC_Os01g62420.1, LOC_Os02g36600.1, and LOC_Os08g37380.2 in the glycolysis/gluconeogenesis pathway, which limit the glycolytic process and decrease the glucose-1-phosphate consumption. In the starch and sucrose metabolic pathway, an up-regulated protein, i.e., LOC_Os06g04200.1 and two down-regulated proteins, i.e., LOC_Os05g32710.1 and LOC_Os04g43360.1 were identified (Figure 4). Glucose-1-phosphate is one of the first substrates in starch synthesis and glycolysis that are catalyzed to form adenosine diphosphate glucose (ADPG), then the ADPG is catalyzed by granule-bound starch synthase Ⅰ (GBSS I) to elongate amylose.Conclusions The results indicate that decreasing the consumption of glucose-1-phosphate in the glycolytic process is essential for the formation of ADPG and UDPG, which are substrates for amylose synthesis. In theory, amylose content in rice can be regulated by controlling the fate of glucose-1-phosphate.

scholarly journals Proteomic profiling reveals differentially expressed proteins associated with amylose accumulation during rice grain filling

2020 ◽  
Author(s):  
Hengdong Zhang ◽  
Jiana Chen ◽  
Shuanglü Shah ◽  
Fangbo Cao ◽  
Guanghui Chen ◽  
...  
Keyword(s):  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Adenosine Diphosphate ◽  
Differentially Expressed ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Differentially Expressed Proteins ◽  
Proteomic Profiling ◽  
Rice Grains

Abstract BackgroundAmylose accumulation in rice grains is controlled by genetic and environmental factors. Amylose content is a determinant factor of rice quality in terms of cooking and eating. Great variations in amylose content in indica rice cultivars have been observed. The current study was to identify differentially expressed proteins in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways and their relationships to amylose synthesis using two rice cultivars possess contrasting phenotypes in grain amylose content.ResultsSynthesis and accumulation of amylose in rice grains significantly affected the variations between rice cultivars in amylose contents. The high amylose content cultivar has three down-regulated differentially expressed proteins, i.e., LOC_Os01g62420.1, LOC_Os02g36600.1, and LOC_Os08g37380.2 in the glycolysis/gluconeogenesis pathway, which limit the glycolytic process and decrease the glucose-1-phosphate consumption. In the starch and sucrose metabolic pathway, an up-regulated protein, i.e., LOC_Os06g04200.1 and two down-regulated proteins, i.e., LOC_Os05g32710.1 and LOC_Os04g43360.1 were identified (Figure 4). Glucose-1-phosphate is one of the first substrates in starch synthesis and glycolysis that are catalyzed to form adenosine diphosphate glucose (ADPG), then the ADPG is catalyzed by granule-bound starch synthase Ⅰ (GBSS I) to elongate amylose.ConclusionsThe results indicate that decreasing the consumption of glucose-1-phosphate in the glycolytic process is essential for the formation of ADPG and UDPG, which are substrates for amylose synthesis. In theory, amylose content in rice can be regulated by controlling the fate of glucose-1-phosphate.

scholarly journals Proteomic Profiling Reveals Differentially Expressed Proteins Associated with Amylose Accumulation During Rice Grain Filling

2020 ◽  
Author(s):  
Hengdong Zhang ◽  
Jiana Chen ◽  
Shuanglü Shah ◽  
Fangbo Cao ◽  
Guanghui Chen ◽  
...  
Keyword(s):  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Adenosine Diphosphate ◽  
Differentially Expressed ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Differentially Expressed Proteins ◽  
Proteomic Profiling ◽  
Rice Grains

Abstract BackgroundAmylose accumulation in rice grains is controlled by genetic and environmental factors. Amylose content is a determinant factor of rice quality in terms of cooking and eating. Great variations in amylose content in indica rice cultivars have been observed. The current study was to identify differentially expressed proteins in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways and their relationships to amylose synthesis using two rice cultivars possess contrasting phenotypes in grain amylose content.ResultsSynthesis and accumulation of amylose in rice grains significantly affected the variations between rice cultivars in amylose contents. The high amylose content variety have three down-regulated differentially expressed proteins, i.e., LOC_Os01g62420.1, LOC_Os02g36600.1, and LOC_Os08g37380.2 in the glycolysis/gluconeogenesis pathway, which limit the glycolytic process and decrease the consumption of glucose-1-phosphate. In the starch and sucrose metabolic pathway, an up-regulated protein, i.e., LOC_Os06g04200.1 and two down-regulated proteins, i.e., LOC_Os05g32710.1 and LOC_Os04g43360.1 were identified (Figure 4). Glucose-1-phosphate is one of the first substrates in starch synthesis and glycolysis that are catalyzed to form adenosine diphosphate glucose (ADPG), then the ADPG is catalyzed by granule-bound starch synthase Ⅰ (GBSS I) to elongate amylose.ConclusionsThe results indicate that decreasing the consumption of glucose-1-phosphate in glycolytic process is essential for the formation of ADPG and UDPG, which are substrates for amylose synthesis. In theory, amylose content in rice can be regulated by controlling the fate of glucose-1-phosphate.

Current status and strategies for improvement of rice grain chalkiness

2009 ◽  
Vol 31 (6) ◽  
pp. 563-572 ◽  
Author(s):  
Li-Jun ZHOU ◽  
Ling JIANG ◽  
Hu-Qu ZHAI ◽  
Jian-Min WAN
Keyword(s):  
Current Status ◽  
Rice Grain ◽  
Grain Chalkiness

scholarly journals Sweet Corn Research around the World 2015–2020

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 534
Author(s):  
Pedro Revilla ◽  
Calli M. Anibas ◽  
William F. Tracy
Keyword(s):  
Sweet Corn ◽  
Starch Content ◽  
Starch Synthesis ◽  
Environmental Care ◽  
Research Activities ◽  
The Us ◽  
The World ◽  
The Usa ◽  
Basic Biology ◽  
Endosperm Starch

Modern sweet corn is distinguished from other vegetable corns by the presence of one or more recessive alleles within the maize endosperm starch synthesis pathway. This results in reduced starch content and increased sugar concentration when consumed fresh. Fresh sweet corn originated in the USA and has since been introduced in countries around the World with increasing popularity as a favored vegetable choice. Several reviews have been published recently on endosperm genetics, breeding, and physiology that focus on the basic biology and uses in the US. However, new questions concerning sustainability, environmental care, and climate change, along with the introduction of sweet corn in other countries have produced a variety of new uses and research activities. This review is a summary of the sweet corn research published during the five years preceding 2021.

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