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 Transcriptomic Analysis of the Maize Mutant TC19 Identifies Genes Regulating the Development of Grain Size Through the IAA and BR Pathways

2021 ◽  
Author(s):  
Yanrong Zhang ◽  
Fuchao Jiao ◽  
Jun Li ◽  
Yuhe Pei ◽  
Meiai Zhao ◽  
...  
Keyword(s):  
Grain Size ◽  
Expression Patterns ◽  
Signal Transduction Pathway ◽  
Grain Filling ◽  
Maize Breeding ◽  
Key Factor ◽  
Cell Components ◽  
Length Width ◽  
Grain Width ◽  
Grain Filling Stage

Abstract Backgrounds: Grain size is a key factor in crop yield that gradually develops after pollination. However, few studies have reported gene expression patterns in maize grain development using mutants. To investigate the developmental mechanisms of grain size, we analyzed a large-grain mutant, named TC19, at the morphological and transcriptome level at five stages corresponding to days after pollination (DAP).Results: After maturation, the grain length, width, and thickness in TC19 were greater than that in Chang 7-2 (control) and increased by 3.57%, 8.80%, and 3.88%, respectively. Further analysis showed that grain width in TC19 was lower than in Chang 7-2 at 7, 14, and 21 DAP, but greater than that in Chang 7-2 at 28 and 35 DAP, indicating that 21 to 28 DAP was the critical stage for kernel width development. For all five stages, the concentrations of indole-3-acetic acid and brassinosteroids were significantly higher in TC19 than in Chang 7-2. Gibberellin was higher at 7, 14, and 21 DAP, and cytokinin was higher at 21 and 35 DAP, in TC19 than in Chang 7-2. Through transcriptome analysis at 14, 21, and 28 DAP, we identified 2987, 2647, and 3209 differentially expressed genes (DEGs) between TC19 and Chang 7-2. Gene Ontology analysis indicated that most of the grain size–related genes corresponded to three aspects, including cell components, molecular functions, and biological processes. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that 77 DEGs were enriched in the plant hormone signal transduction pathway. We further analyzed several highly expressed candidate genes, including AO2, ARF3, and IAA15, which are involved in the synthesis of IAA; and DWF4 and XTH, which are involved in the synthesis of BR.Conclusions: Our results elucidated the mechanisms of grain size development at the grain-filling stage and have potential application in maize breeding.

scholarly journals Grain Size Selection Using Novel Functional Markers Targeting 14 Genes in Rice

Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Lin Zhang ◽  
Bin Ma ◽  
Zhong Bian ◽  
Xiaoyuan Li ◽  
Changquan Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Rational Design ◽  
Width Ratio ◽  
Functional Markers ◽  
Rice Breeding ◽  
Nucleotide Polymorphisms ◽  
Yield And Quality ◽  
Grain Width ◽  
Grain Yield And Quality

Abstract Background Grain size is an extremely important aspect of rice breeding, affecting both grain yield and quality traits. It is controlled by multiple genes and tracking these genes in breeding schemes should expedite selection of lines with superior grain yield and quality, thus it is essential to develop robust, efficient markers. Result In this study, 14 genes related to grain size (GW2, GS2, qLGY3, GS3, GL3.1, TGW3, GS5, GW5, GS6, TGW6, GW6a, GLW7, GL7 and GW8) were selected for functional marker development. Twenty-one PCR-gel-based markers were developed to genotype the candidate functional nucleotide polymorphisms (FNPs) of these genes, and all markers can effectively recognize the corresponding allele types. To test the allele effects of different FNPs, a global collection of rice cultivars including 257 accessions from the Rice Diversity Panel 1 was used for allele mining, and four grain-size-related traits were investigated at two planting locations. Three FNPs for GW2, GS2 and GL3.1 were genotyped as rare alleles only found in cultivars with notably large grains, and the allele contributions of the remaining FNPs were clarified in both the indica and japonica subspecies. Significant trait contributions were found for most of the FNPs, especially GS3, GW5 and GL7. Of note, GW5 could function as a key regulator to coordinate the performance of other grain size genes. The allele effects of several FNPs were also tested by QTL analysis using an F2 population, and GW5 was further identified as the major locus with the largest contribution to grain width and length to width ratio. Conclusions The functional markers are robust for genotyping different cultivars and may facilitate the rational design of grain size to achieve a balance between grain yield and quality in future rice breeding efforts.

scholarly journals Substitution Mapping of Two Closely Linked QTLs Controlling Grain Chalkiness and Grain Shape on Rice Chromosome 8

2021 ◽  
Author(s):  
Weifeng Yang ◽  
Liang Xiong ◽  
Jiayan Liang ◽  
Qingwen Hao ◽  
Xin Luan ◽  
...  
Keyword(s):  
Grain Quality ◽  
Grain Shape ◽  
Rice Chromosome ◽  
Chromosome 8 ◽  
High Yield ◽  
Rice Grain ◽  
Rice Varieties ◽  
Substitution Mapping ◽  
Grain Width ◽  
Grain Chalkiness

Abstract Background: Rice varieties are required to have high yield and good grain quality. Grain chalkiness and grain shape are two important traits of rice grain quality. Low chalkiness slender grains are preferred by most rice consumers. Here, we dissected two closely linked quantitative trait loci (QTLs) controlling grain chalkiness and grain shape on rice chromosome 8 by substitution mapping. Results: Two closely linked QTLs controlling grain chalkiness and grain shape were identified using single-segment substitution lines (SSSLs). The two QTLs were then dissected on rice chromosome 8 by secondary substitution mapping. qPGC8.1 was located in an interval of 1382.6 kb and qPGC8.2 was mapped in a 2057.1 kb region. The maximum distance of the two QTLs was 4.37 Mb and the space distance of two QTL intervals was 0.72 Mb. qPGC8.1 controlled grain chalkiness and grain width. qPGC8.2 was responsible for grain chalkiness and for grain length and grain width. The additive effects of qPGC8.1 and qPGC8.2 on grain chalkiness were not affected by heat stress. Conclusions: Two closely linked QTLs qPGC8.1 and qPGC8.2 were dissected on rice chromosome 8. They controlled the phenotypes of grain chalkiness and grain shape. The two QTLs were insensitive to high temperature.

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 Development of Chlorophyll-Meter-Index-Based Dynamic Models for Evaluation of High-Yield Japonica Rice Production in Yangtze River Reaches

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 106 ◽  
Author(s):  
Ke Zhang ◽  
Xiaojun Liu ◽  
Syed Tahir Ata-Ul-Karim ◽  
Jingshan Lu ◽  
Brian Krienke ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
High Yield ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Rice Grain ◽  
Japonica Rice ◽  
Ripening Period ◽  
The Third ◽  
Different Growth Stages

Accurate estimation of the nitrogen (N) spatial distribution of rice (Oryza sativa L.) is imperative when it is sought to maintain regional and global carbon balances. We systematically evaluated the normalized differences of the soil and plant analysis development (SPAD) index (the normalized difference SPAD indexes, NDSIs) between the upper (the first and second leaves from the top), and lower (the third and fourth leaves from the top) leaves of Japonica rice. Four multi-location, multi-N rate (0–390 kg ha−1) field experiments were conducted using seven Japonica rice cultivars (9915, 27123, Wuxiangjing14, Wunyunjing19, Wunyunjing24, Liangyou9, and Yongyou8). Growth analyses were performed at different growth stages ranging from tillering (TI) to the ripening period (RP). We measured leaf N concentration (LNC), the N nutrition index (NNI), the NDSI, and rice grain yield at maturity. The relationships among the NDSI, LNC, and NNI at different growth stages showed that the NDSI values of the third and fourth fully expanded leaves more reliably reflected the N nutritional status than those of the first and second fully expanded leaves (LNC: NDSIL3,4, R2 > 0.81; NDSIothers, 0.77 > R2 > 0.06; NNI: NDSIL3,4, R2 > 0.83; NDSIothers, 0.76 > R2 > 0.07; all p < 0.01). Two new diagnostic models based on the NDSIL3,4 (from the tillering to the ripening period) can be used for effective diagnosis of the LNC and NNI, which exhibited reasonable distributions of residuals (LNC: relative root mean square error (RRMSE) = 0.0683; NNI: RRMSE = 0.0688; p < 0.01). The relationship between grain yield, predicted yield, and NDSIL3,4 were established during critical growth stages (from the stem elongation to the heading stages; R2 = 0.53, p < 0.01, RRMSE = 0.106). An NDSIL3,4 high-yield change curve was drawn to describe critical NDSIL3,4 values for a high-yield target (10.28 t ha−1). Furthermore, dynamic-critical curve models based on the NDSIL3,4 allowed a precise description of rice N status, facilitating the timing of fertilization decisions to optimize yields in the intensive rice cropping systems of eastern China.

scholarly journals Generation of High Yielding and Fragrant Rice (Oryza sativa L.) Lines by CRISPR/Cas9 Targeted Mutagenesis of Three Homoeologs of Cytochrome P450 Gene Family and OsBADH2 and Transcriptome and Proteome Profiling of Revealed Changes Triggered by Mutations

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 788 ◽  
Author(s):  
Babar Usman ◽  
Gul Nawaz ◽  
Neng Zhao ◽  
Yaoguang Liu ◽  
Rongbai Li
Keyword(s):  
Grain Size ◽  
Cytochrome P450 ◽  
Grain Yield ◽  
Rna Sequencing ◽  
Oryza Sativa L ◽  
Targeted Mutagenesis ◽  
High Yield ◽  
Yield And Quality ◽  
Target Sites ◽  
Cytochrome P450 Family

The significant increase in grain yield and quality are often antagonistic but a constant demand for breeders and consumers. Some genes related to cytochrome P450 family are known for rice organ growth but their role in controlling grain yield is still unknown. Here, we generated new rice mutants with high yield and improved aroma by simultaneously editing three cytochrome P450 homoeologs (Os03g0603100, Os03g0568400, and GL3.2) and OsBADH2 with the CRISPR/Cas9 system, and RNA-sequencing and proteomic analysis were performed to unveil the subsequent changes. High mutation efficiency was achieved in both target sites of each gene and the mutations were predominantly only deletions, while insertions were rare, and no mutations were detected in the five most likely off-target sites against each sgRNA. Mutants exhibited increased grain size, 2-acetyl-1-pyrroline (2AP) content, and grain cell numbers while there was no change in other agronomic traits. Transgene-DNA-free mutant lines appeared with a frequency of 44.44% and homozygous mutations were stably transmitted, and bi-allelic and heterozygous mutations followed Mendelian inheritance, while the inheritance of chimeric mutations was unpredictable. Deep RNA sequencing and proteomic results revealed the regulation of genes and proteins related to cytochrome P450 family, grain size and development, and cell cycle. The KEGG and hub-gene and protein network analysis showed that the gene and proteins related to ribosomal and photosynthesis pathways were mainly enriched, respectively. Our findings provide a broad and detailed basis to understand the role of CRISPR/Cas9 in rice yield and quality improvement.

Studies of grain production in Sorghum bicolor (L. Moench). III.* The relative importance of assimilate supply, grain growth capacity and transport system

1975 ◽  
Vol 26 (1) ◽  
pp. 11 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Transport System ◽  
Dry Matter ◽  
Storage Capacity ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Plant Parts ◽  
Root Potential ◽  
Sorghum Bicolor L

In field and glasshouse experiments with grain sorghum (cv. RS610), the assimilate supply was varied by increasing or decreasing radiation and carbon dioxide supply; the potential grain storage capacity was altered by spikelet removal; and the transport system was reduced by incision of the culm. Plants grown at four population densities in the field were manipulated to increase (by removing neighbouring plants) or decrease (by shading) the supply of photosynthates during grain filling. These treatments affected grain size and thus yield. Removal of some of the spikelets at three-quarter anthesis resulted in a significant increase in the size of those grains remaining at maturity. From anthesis onward, a reduction in the capacity of the transport system in the culm had no significant effect on grain yield. These results are interpreted as evidence that grain yield is not limited by the storage capacity of the grain, or by the transport system involved in moving material from the stem to the grain. Treatments which altered the demand for assimilates by the grain, relative to the supply, did not affect net photosynthesis. Dry matter produced in excess of grain requirements accumulated in other plant parts, including the root. Potential grain size was influenced by interspikelet competition operating within 1 week after three-quarter anthesis. *Part II, Aust. J. Agric. Res., 22: 39-47 (1971).

Responsiveness of barley cultivars to nitrogen fertiliser

1997 ◽  
Vol 37 (2) ◽  
pp. 199 ◽  
Author(s):  
G. Fathi ◽  
G. K. McDonald ◽  
R. C. M. Lance
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Initial Response ◽  
Kernel Weight ◽  
High Yield ◽  
Malting Quality ◽  
Yield Response ◽  
Genotypic Differences ◽  
Barley Cultivars ◽  
N Rates

Summary. Genotypic differences in responses to nitrogen (N) fertiliser of 6 cultivars of barley (Clipper, Stirling, Weeah, Schooner, Chebec, Skiff) grown at 8 different rates of N were examined in 2 seasons. Measurements of vegetative growth, N content, grain yield, grain protein concentration (GPC) and yield components were taken to identify traits that may contribute to high yield responsiveness. The optimum rates of N for dry matter production at ear emergence (DMee) were greater than 80 kg N/ha for all cultivars and often growth increased up to 105 kg N/ha. Optimum rates of N for grain yield (Nopt) were lower and ranged, on average, from 50 kg N/ha for Clipper to 96 kg N/ha for Chebec. The initial response to N varied from 13–14 kg/kg N in Chebec, Weeah and Schooner, to 36 kg/kg N in Skiff. The Nopt for the semi-dwarf cultivar Skiff was 71 kg N/ha and it tended to show the greatest yield response to N. It produced 19 kernels/g DMee, compared with 15–17 kernels/g DMee in the other cultivars. Unlike most other cultivars, Skiff’s yield was consistently and positively correlated with ears/m2; Stirling was the only other cultivar to show a similar relationship. However, the average kernel weight of Skiff was up to 5 mg lower than that of Clipper, Weeah and Schooner, and varied more than these cultivars between sites, suggesting that consistent grain size may be a problem in this cultivar. By comparison, Clipper and Schooner had lower Nopt (51 kg/ha) and a less variable kernel weight. There were no signs of differences in GPC of the 6 cultivars used here at 3 N-responsive sites. Adding N increased GPC up to the highest rate of N and the responses were generally linear, but GPC at Nopt exceeded the upper limit for malting quality of 11.8% in all cultivars. Average N rates of between 38 kg N/ha (Schooner) and 58 kg N/ha (Skiff) were sufficient to raise GPC above 11.8%. The experiments showed that the N rates for optimum yields varied considerably among cultivars, but applyi1ng rates to achieve maximum yields may cause GPC to exceed the maximum value for malting barley. The use of semi-dwarf cultivars, such as Skiff, which are very responsive to N, can provide some leeway in the choice of N, but there may be a trade-off in quality associated with reduced grain size.

scholarly journals GW10, a Member of P450 Subfamily Regulates Grain Size and Grain Number in Rice

2021 ◽  
Author(s):  
PengLin Zhan ◽  
Xin Wei ◽  
Zhili Xiao ◽  
Xiaoling Wang ◽  
Shuaipeng Ma ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Grain Shape ◽  
Rice Grain ◽  
Chromosome 10 ◽  
Grain Number ◽  
Tropical Japonica ◽  
Donor Parent ◽  
Lower Expression ◽  
Recipient Parent

Abstract Grain size and grain number play extremely important roles in rice grain yield. Here, we identify GW10 , which encodes a P450 subfamily protein and controlls grain size and grain number by using Lemont ( tropical japonica ) as donor parent and HJX74 ( indica ) as recipient parent. The GW10 locus was mapped into a 20.1 kb region on the long arm of Chromosome 10. Lower expression of the gw10 in panicle is contributed to the shorter and narrower rice grain, and the increased number of grains per panicle. Furthermore, the higher expression levels of some of the brassinosteroid (BR) biosynthesis and response genes are associated with the NIL- GW10 , which strongly suggests that the GW10 is a key node in the brassinosteroid-mediated regulation of rice grain shape and grain number.

Effects of Growth Regulators on Fruiting and Yield of Black Gram (Phaseolus Mungo, Roxb.) in India

1968 ◽  
Vol 4 (4) ◽  
pp. 339-344 ◽  
Author(s):  
O. N. Mehrotra ◽  
H. K. Saxena ◽  
A. N. Roy ◽  
Shiva Nath
Keyword(s):  
Grain Size ◽  
Gibberellic Acid ◽  
Grain Yield ◽  
Growth Regulators ◽  
Grain Filling ◽  
Naphthaleneacetic Acid ◽  
Black Gram ◽  
Economic Returns ◽  
Phaseolus Mungo ◽  
Chlorophenoxyacetic Acid

SUMMARYAn experiment was conducted in 1964 and 1965 to study the effects of hormone sprays on pod setting, pod filling and grain yield of black gram. Sprays of 2-naphthoxyacetic acid and p-chlorophenoxyacetic acid, alone and in 'mixture, and gibberellic acid and 1-naphthaleneacetic acid increased pod setting, but grain filling in pods and grain size were only slightly improved. 2-naphthoxyacetic acid gave the highest yield, followed by p-chlorophenoxyacetic acid, 1-naphthaleneacetic acid and a mixture of the first two, which increased yield by 56, 39, 36 and 35 per cent respectively over the control and gave economic returns.

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