The Rapid Cytological Process of Grain Determines Early Maturity in Weedy Rice

Shorter grain-filling period and rapid endosperm development endow weedy rice (WR) with early maturity compared to cultivated rice (CR). However, the role of the cytological features and antioxidative enzyme system during grain development are largely unexplored. We selected four biotypes of WR and their associated cultivated rice (ACR) types from different latitudes to conduct a common garden experiment. The difference in the cytological features of endosperm between WR and ACR was compared by chemical staining, and the cell viability and nuclear morphometry of endosperm cells were observed by optical microscopy. Furthermore, antioxidative enzyme activity was measured during grain filling. Anatomic observation of endosperm shows that the development process of endosperm cell in WR was more rapid and earlier than that in ACR. The percentage of degraded nuclei of WR was 2–83% more than that of ACR. Endosperm cells in WR lost viability 2–6 days earlier than those in ACR. The antioxidant enzyme activity of WR was lower than that of ACR during grain filling. The ability of WR to scavenge reactive oxygen species (ROS) was weaker than that of ACR, which may contribute to the rapid cytological process in the endosperm cells of WR. The rapid cytological process and weaker ability to scavenge ROS in endosperm cells may contribute to early maturity in WR.

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Rapid endosperm development promotes early maturity in weedy rice (Oryza sativa f. spontanea)

Weed Science ◽

10.1017/wsc.2020.5 ◽

2020 ◽

Vol 68 (2) ◽

pp. 168-178

Author(s):

Can Zhao ◽

Wenrong Xu ◽

Lingchao Meng ◽

Sheng Qiang ◽

Weimin Dai ◽

...

Keyword(s):

Oryza Sativa ◽

Cell Division ◽

Grain Filling ◽

Endosperm Development ◽

Starch Accumulation ◽

Weedy Rice ◽

Endosperm Cell ◽

Cultivated Rice ◽

Early Maturity ◽

Grain Filling Period

AbstractEarly maturity allows weedy rice (Oryza sativa L. f. spontanea) to persist by escaping harvest in paddy fields. A shorter grain-filling period contributes to the early maturity of weedy rice. However, the differences in morphology and endosperm development in the caryopsis between weedy and cultivated rice are largely unexplored. Here, we selected four biotypes of weedy rice and associated cultivated rice (ACR; Oryza sativa) from different latitudes to conduct a common garden experiment. The endosperm development process of the caryopsis was observed by optical microscopy and electron microscopy. Endosperm cell division and starch accumulation rate during grain filling were also measured. The grain development progress in weedy rice was more rapid and earlier than that in ACR. The endosperm development progress of weedy rice was 6 to 8 d earlier than that of ACR. The endosperm cells of weedy rice cellularized earlier and more rapidly than those of ACR, and the starch grains of weedy rice were more sharply polygonal and compactly arranged than those of ACR. The active endosperm cell division period in weedy rice was 4 to 7 d shorter than that in ACR, while the active starch accumulation period of weedy rice was 2 to 8 d shorter than that of ACR. The rapid development of endosperm cells and starch grains leads to the shorter grain-filling period of weedy rice. weedy rice.

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Rapid PCD Process Promotes Early Maturity in Weedy Rice (Oryza sativa L. f. spontanea)

10.21203/rs.3.rs-75420/v1 ◽

2020 ◽

Author(s):

Can Zhao ◽

Wenrong Xu ◽

Zheng Zhang ◽

Lingchao Meng ◽

Weimin Dai ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Oryza Sativa ◽

Cell Viability ◽

Grain Filling ◽

Oxidative Enzymes ◽

Weedy Rice ◽

Oxygen Species ◽

Cultivated Rice ◽

Early Maturity ◽

Grain Filling Period

Abstract Background: Shorter grain-filling period and rapid endosperm development contributes to early maturity in weedy rice (Oryza sativa L. f. spontanea). However, the differences in programmed cell death (PCD) process and anti-oxidative enzymes system in the caryopsis between weedy and cultivated rice are largely unexplored. Main Text: we selected four biotypes of weedy rice and associated cultivated rice (ACR, Oryza sativa) from different latitudes to conduct a common garden experiment. The difference of PCD process between weedy rice and ACR was compared by chemical staining, and the cell viability and nuclear morphometry of endosperm cells were observed by optical microscopy, and anti-oxidative enzymes activity were also measured during grain filling. We found that the PCD progress in weedy rice was more rapid and earlier than that in ACR. The percentage of degraded nuclei of weedy rice were 10%-83% higher than that of ACR. Endosperm cells in weedy rice lost cell viability 2-8 days earlier than that in ACR. The anti-oxidant enzymes activity of weedy rice were lower than that of ACR during grain filling. The ability of weedy rice to scavenge reactive oxygen species is weaker than that of ACR, which may contribute to the rapid PCD process in the endosperm cells of weedy rice. Conclusion: The rapid PCD process and weaker ability to scavenge reactive oxygen species in endosperm cells lead to the shorter grain-filling period of weedy rice.

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Early flowering and rapid grain filling determine early maturity and escape from harvesting in weedy rice

Pest Management Science ◽

10.1002/ps.4730 ◽

2017 ◽

Vol 74 (2) ◽

pp. 465-476 ◽

Cited By ~ 3

Author(s):

Can Zhao ◽

Wenrong Xu ◽

Xiaoling Song ◽

Weimin Dai ◽

Lei Dai ◽

...

Keyword(s):

Grain Filling ◽

Early Flowering ◽

Weedy Rice ◽

Early Maturity

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Comparative transcriptomic and physiological analyses of weedy rice and cultivated rice to identify vital differentially expressed genes and pathways regulating the ABA response

Scientific Reports ◽

10.1038/s41598-021-92504-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hong Lang ◽

Yuting He ◽

Faliang Zeng ◽

Fan Xu ◽

Minghui Zhao ◽

...

Keyword(s):

Differentially Expressed Genes ◽

Differentially Expressed ◽

Weedy Rice ◽

Cultivated Rice ◽

Biotic Stresses ◽

Aba Sensitivity ◽

Aba Catabolism ◽

Physiological Analysis ◽

Response To Stress ◽

Aba Response

AbstractWeedy rice is a valuable germplasm resource characterized by its high tolerance to both abiotic and biotic stresses. Abscisic acid (ABA) serves as a regulatory signal in plant cells as part of their adaptive response to stress. However, a global understanding of the response of weedy rice to ABA remains to be elucidated. In the present study, the sensitivity to ABA of weedy rice (WR04-6) was compared with that of temperate japonica Shennong9816 (SN9816) in terms of seed germination and post-germination growth via the application of exogenous ABA and diniconazole, an inhibitor of ABA catabolism. Physiological analysis and a transcriptomic comparison allowed elucidation of the molecular and physiological mechanisms associated with continuous ABA and diniconazole treatment. WR04-6 was found to display higher ABA sensitivity than SN9816, resulting in the rapid promotion of antioxidant enzyme activity. Comparative transcriptomic analyses indicated that the number of differentially expressed genes (DEGs) in WR04-6 seedlings treated with 2 μM ABA or 10 μM diniconazole was greater than that in SN9816 seedlings. Genes involved in stress defense, hormone signal transduction, and glycolytic and citrate cycle pathways were highly expressed in WR04-6 in response to ABA and diniconazole. These findings provide new insight into key processes mediating the ABA response between weedy and cultivated rice.

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Antioxidant Enzyme Levels Inversely Covary with Hearing Loss After Amikacin Treatment

Journal of the American Academy of Audiology ◽

10.1055/s-0040-1715718 ◽

2003 ◽

Vol 14 (03) ◽

pp. 134-143 ◽

Cited By ~ 6

Author(s):

James J. Klemens ◽

Robert P. Meech ◽

Larry F. Hughes ◽

Satu Somani ◽

Kathleen C.M. Campbell

Keyword(s):

Hearing Loss ◽

Enzyme Activity ◽

Antioxidant Enzyme ◽

Guinea Pigs ◽

Auditory Brainstem ◽

Antioxidant Enzyme Activity ◽

Control Group ◽

Glutathione S Transferase ◽

Brainstem Response ◽

The Difference

This study's purpose was to determine if a correlation exists between cochlear antioxidant activity changes and auditory function after induction of aminoglycoside (AG) ototoxicity. Two groups of five 250-350 g albino guinea pigs served as subjects. For 28 days, albino guinea pigs were administered either 200 mg/kg/day amikacin, or saline subcutaneously. Auditory brainstem response testing was performed prior to the first injection and again before sacrifice, 28 days later. Cochleae were harvested and superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase activities and malondialdehyde levels were measured. All antioxidant enzymes had significantly lower activity in the amikacin group (p ≤ 0.05) than in the control group. The difference in cochlear antioxidant enzyme activity between groups inversely correlated significantly with the change in ABR thresholds. The greatest correlation was for the high frequencies, which are most affected by aminoglycosides. This study demonstrates that antioxidant enzyme activity and amikacin-induced hearing loss significantly covary.

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Weedy Rice Diversity in Southern Brazil

Weed Science ◽

10.1017/wsc.2021.23 ◽

2021 ◽

pp. 1-37

Author(s):

Leonard Bonilla Piveta ◽

José Alberto Noldin ◽

Nilda Roma-Burgos ◽

Vívian Ebeling Viana ◽

Lariza Benedetti ◽

...

Keyword(s):

Oryza Sativa ◽

Flowering Time ◽

Weed Management ◽

Phenotypic Diversity ◽

Weedy Rice ◽

Phenotypic Traits ◽

Southern Brazil ◽

Variable Response ◽

Cultivated Rice ◽

Flowering Synchrony

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.

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Explore the genetics of weedy traits using rice 3K database

Botanical Studies ◽

10.1186/s40529-020-00309-y ◽

2021 ◽

Vol 62 (1) ◽

Author(s):

Yu-Lan Lin ◽

Dong-Hong Wu ◽

Cheng-Chieh Wu ◽

Yung-Fen Huang

Keyword(s):

Seed Coat ◽

Coat Color ◽

Rice Genome ◽

Genome Project ◽

Weedy Rice ◽

Seed Coat Color ◽

Allele Mining ◽

Cultivated Rice ◽

Population Structure Analysis ◽

Public Data

Abstract Background Weedy rice, a conspecific weedy counterpart of the cultivated rice (Oryza sativa L.), has been problematic in rice-production area worldwide. Although we started to know about the origin of some weedy traits for some rice-growing regions, an overall assessment of weedy trait-related loci was not yet available. On the other hand, the advances in sequencing technologies, together with community efforts, have made publicly available a large amount of genomic data. Given the availability of public data and the need of “weedy” allele mining for a better management of weedy rice, the objective of the present study was to explore the genetic architecture of weedy traits based on publicly available data, mainly from the 3000 Rice Genome Project (3K-RGP). Results Based on the results of population structure analysis, we have selected 1378 individuals from four sub-populations (aus, indica, temperate japonica, tropical japonica) without admixed genomic composition for genome-wide association analysis (GWAS). Five traits were investigated: awn color, seed shattering, seed threshability, seed coat color, and seedling height. GWAS was conducted for each sub-population × trait combination and we have identified 66 population-specific trait-associated SNPs. Eleven significant SNPs fell into an annotated gene and four other SNPs were close to a putative candidate gene (± 25 kb). SNPs located in or close to Rc were particularly predictive of the occurrence of seed coat color and our results showed that different sub-populations required different SNPs for a better seed coat color prediction. We compared the data of 3K-RGP to a publicly available weedy rice dataset. The profile of allele frequency, phenotype-genotype segregation of target SNP, as well as GWAS results for the presence and absence of awns diverged between the two sets of data. Conclusions The genotype of trait-associated SNPs identified in this study, especially those located in or close to Rc, can be developed to diagnostic SNPs to trace the origin of weedy trait occurred in the field. The difference of results from the two publicly available datasets used in this study emphasized the importance of laboratory experiments to confirm the allele mining results based on publicly available data.

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Economic optimum plant density of irrigated early-maturity soybean in southern Alberta

Canadian Journal of Plant Science ◽

10.1139/cjps-2021-0026 ◽

2021 ◽

Author(s):

Tram T.N. Thai ◽

Danny G. Le Roy ◽

Manjula S. Bandara ◽

James E. Thomas ◽

Francis J Larney

Keyword(s):

Plant Density ◽

Profit Maximization ◽

Seeding Density ◽

Early Maturity ◽

Growing Seasons ◽

Southern Alberta ◽

Soybean Genotypes ◽

Glycine Max L ◽

The Difference ◽

Lower Plant

With soybean [Glycine max (L.) Merr.] seed cost increasing in Alberta, understanding economic optimum plant density (EOPD) could help growers save on input expenses. A study was conducted at two irrigated locations in southern Alberta (Bow Island and Lethbridge), in three growing seasons (2014–16), using two maturity group (MG) 00 soybean genotypes, two row spacings (RS; narrow, 17.5 cm; wide, 35 cm), and three seeding densities (SD; 30, 50 and 80 seeds m-2). Exponential plant density-yield relationships were used to estimate EOPD. The earlier MG 00.4 genotype compensated yield at lower plant density (39 vs. 43 plants m-2) and emergence (74 vs. 80%) than the later MG 00.8 genotype. The EOPD gaps between environments, genotypes, and RS were minimal (from 1–3 plants m-2), resulting in only 1.3–2.0% differences in grain yield (37–56 kg ha-1), and gross revenue at EOPD ($16–24 ha-1). The overall EOPD estimate was 46 plants m-2, regardless of environment, genotype or RS. The study highlighted the difference between agronomic production and profit maximization in choosing an optimum plant density, and the need to establish a seeding density calculator for irrigated soybean in southern Alberta.

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