scholarly journals Role of the Leaf Sheath in Elongation of the Internodes of Rice Plants.

1992 ◽  
Vol 61 (2) ◽  
pp. 235-243
Author(s):  
Kiyoshi TAKAHASHI
Keyword(s):  
Leaf Sheath ◽  
Rice Plants

scholarly journals Small virus-like particles isolated from the leaf sheath tissues of rice plants and from the rice tarsonemid mites, Steneotarsonemus spinki smiley (Acarina, Tarsonemidae).

1984 ◽  
Vol 50 (3) ◽  
pp. 368-374 ◽  
Author(s):  
Eishiro SHIKATA ◽  
Shinji KAWANO ◽  
Toshihiro SENBOKU ◽  
Emmanuel R. TIONGCO ◽  
Kuniyuki MIYAJIMA
Keyword(s):  
Leaf Sheath ◽  
Virus Like Particles ◽  
Rice Plants ◽  
Small Virus

scholarly journals The Role of Catalase-Peroxidase Secreted by Magnaporthe oryzae During Early Infection of Rice Cells

2011 ◽  
Vol 24 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Shigeru Tanabe ◽  
Naoko Ishii-Minami ◽  
Ken-Ichiro Saitoh ◽  
Yuko Otake ◽  
Hanae Kaku ◽  
...  
Keyword(s):  
Culture Filtrate ◽  
Magnaporthe Oryzae ◽  
Early Stage ◽  
Major Gene ◽  
Leaf Sheath ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Conidial Suspension ◽  
Catalase Peroxidase

The biological role of a secretory catalase of the rice blast fungus Magnaporthe oryzae was studied. The internal amino acid sequences of the partially purified catalase in the culture filtrate enabled us to identify its encoding gene as a catalase-peroxidase gene, CPXB, among four putative genes for catalase or catalase-peroxidase in M. oryzae. Knockout of the gene drastically reduced the level of catalase activity in the culture filtrate and supernatant of conidial suspension (SCS), and increased the sensitivity to exogenously added H2O2 compared with control strains, suggesting that CPXB is the major gene encoding the secretory catalase and confers resistance to H2O2 in hyphae. In the mutant, the rate of appressoria that induced accumulation of H2O2 in epidermal cells of the leaf sheath increased and infection at early stages was delayed; however, the formation of lesions in the leaf blade was not affected compared with the control strain. These phenotypes were complimented by reintroducing the putative coding regions of CPXB driven by a constitutive promoter. These results suggest that CPXB plays a role in fungal defense against H2O2 accumulated in epidermal cells of rice at the early stage of infection but not in pathogenicity of M. oryzae.

scholarly journals The role of silicon in metabolic acclimation of rice plants challenged with arsenic

2016 ◽  
Vol 123 ◽  
pp. 22-36 ◽  
Author(s):  
Lílian M.V.P. Sanglard ◽  
Kelly C. Detmann ◽  
Samuel C.V. Martins ◽  
Rodrigo A. Teixeira ◽  
Lucas F. Pereira ◽  
...  
Keyword(s):  
Rice Plants

Role of peroxidases in the compensation of cytosolic ascorbate peroxidase knockdown in rice plants under abiotic stress

2011 ◽  
Vol 34 (10) ◽  
pp. 1705-1722 ◽  
Author(s):  
AURENIVIA BONIFACIO ◽  
MARCIO O. MARTINS ◽  
CAROLINA W. RIBEIRO ◽  
ADILTON V. FONTENELE ◽  
FABRICIO E. L. CARVALHO ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Ascorbate Peroxidase ◽  
Rice Plants ◽  
Cytosolic Ascorbate Peroxidase

scholarly journals Effects of Elevated Atmospheric CO2 Concentration on the Infection of Rice Blast and Sheath Blight

2006 ◽  
Vol 96 (4) ◽  
pp. 425-431 ◽  
Author(s):  
T. Kobayashi ◽  
K. Ishiguro ◽  
T. Nakajima ◽  
H. Y. Kim ◽  
M. Okada ◽  
...  
Keyword(s):  
Rice Blast ◽  
Soil Surface ◽  
Co2 Concentration ◽  
Leaf Sheath ◽  
Sheath Blight ◽  
Average Height ◽  
Leaf Blast ◽  
Elevated Atmospheric Co2 ◽  
Rice Plants ◽  
Sheath Blight Disease

The effect of elevated atmospheric CO2 concentration on rice blast and sheath blight disease severity was studied in the field in northern Japan for 3 years. With free-air CO2 enrichment (FACE), rice plants were grown in ambient and elevated (≈200 to 280 μmol mol-1 above ambient) CO2 concentrations, and were artificially inoculated with consist of Magnaporthe oryzae. Rice plants grown in an elevated CO2 concentration were more susceptible to leaf blast than those in ambient CO2 as indicated by the increased number of leaf blast lesions. Plants grown under elevated CO2 concentration had lower leaf silicon content, which may have contributed to the increased susceptibility to leaf blast under elevated CO2 concentrations. In contrast to leaf blast, panicle blast severity was unchanged by the CO2 enrichment under artificial inoculation, whereas it was slightly but significantly higher under elevated CO2 concentrations in a spontaneous rice blast epidemic. For naturally occurring epidemics of the sheath blight development in rice plants, the percentage of diseased plants was higher under elevated as opposed to ambient CO2 concentrations. However, the average height of lesions above the soil surface was similar between the treatments. One hypothesis is that the higher number of tillers observed under elevated CO2 concentrations may have increased the chance for fungal sclerotia to adhere to the leaf sheath at the water surface. Consequently, the potential risks for infection of leaf blast and epidemics of sheath blight would increase in rice grown under elevated CO2 concentration.

scholarly journals Comparative study on the influence of silicon and selenium to mitigate arsenic induced stress by modulating TCA cycle, GABA and polyamine synthesis in rice seedlings

2021 ◽  
Author(s):  
Susmita Das ◽  
Barsha Majumder ◽  
Asok Kumar Biswas
Keyword(s):  
Tca Cycle ◽  
Future Application ◽  
Rice Seedlings ◽  
Respiratory Enzymes ◽  
Rice Plants ◽  
Regulatory Enzymes ◽  
Joint Application ◽  
Defensive Role ◽  
Gaba Accumulation

Abstract Arsenic contamination of groundwater is a major concern for its use as drinking water and crop irrigation in many regions of the world. Arsenic is absorbed by rice plants from arsenic contaminated water during irrigation, hampers growth and agricultural productivity. The aim of the study was to mitigate the activity of TCA cycle, synthesis of γ-aminobutyric acid (GABA) and polyamines (PAs) in rice (Oryza sativa L. cv. MTU-1010) seedlings under arsenate (As-V) stress [25 µM, 50 µM and 75 µM] by silicon (Si) [2 mM] and selenium (Se) [5 µM] amendments, and to investigate which chemical was more potential to combat this threat. As(V) application decreased the activities of tested respiratory enzymes while the levels of organic acids (OAs) were increased in the test seedlings. Co-application of Si and As(V) increased the activities of respiratory enzymes, consequently further increased accumulation of OAs that were more than Se with As(V) application in the test seedlings. GABA accumulation along with the activities of its regulatory enzymes were enhanced under As(V) stress. During joint application of Si and As(V) and Se and As(V) said parameters were decreased showing defensive role of these chemicals to resist As(V) toxicity in rice but amendment of Si was more potential than Se amendment resulted reduction of stress induced damage in the test seedlings. PAs trigger tolerance mechanism against stress in plants. PAs viz., Putrescine, spermidine and spermine were synthesized more during Si and Se amendments in As(V) contaminated rice seedlings to combat the effect of stress. Si amendment substantially modulated the toxic effects caused by As(V) over Se amendment in As(V) challenged test seedlings. Thus in future application Si enriched fertilizer will be beneficial than application of Se enriched fertilizer to grow rice plants with normal vigor in arsenic contaminated soil.

scholarly journals The Overlooked Biomechanical Role of the Clasping Leaf Sheath in Wheat Stalk Lodging

2021 ◽  
Vol 12 ◽  
Author(s):  
Joseph Cornwall ◽  
Christopher J. Stubbs ◽  
Christopher S. McMahan ◽  
Daniel J. Robertson
Keyword(s):  
Bending Strength ◽  
Flexural Rigidity ◽  
Leaf Sheath ◽  
Effective Diameter ◽  
Lodging Resistance ◽  
Failure Patterns ◽  
Bending Loads ◽  
Stalk Lodging ◽  
Biomechanical Factors

The biomechanical role of the clasping leaf sheath in stalk lodging events has been historically understudied. Results from this study indicate that in some instances the leaf sheath plays an even larger role in reinforcing wheat against stalk lodging than the stem itself. Interestingly, it appears the leaf sheath does not resist bending loads by merely adding more material to the stalk (i.e., increasing the effective diameter). The radial preload of the leaf sheath on the stem, the friction between the sheath and the stem and several other complex biomechanical factors may contribute to increasing the stalk bending strength and stalk flexural rigidity of wheat. Results demonstrated that removal of the leaf sheath induces alternate failure patterns in wheat stalks. In summary the biomechanical role of the leaf sheath is complex and has yet to be fully elucidated. Many future studies are needed to develop high throughput phenotyping methodologies and to determine the genetic underpinnings of the clasping leaf sheath and its relation to stalk lodging resistance. Research in this area is expected to improve the lodging resistance of wheat.

Fundamental parenchyma cells are involved in Na+ and Cl– removal ability in rice leaf sheath

2019 ◽  
Vol 46 (8) ◽  
pp. 743 ◽  
Author(s):  
Sarin Neang ◽  
Marjorie de Ocampo ◽  
James A. Egdane ◽  
John D. Platten ◽  
Abdelbagi M. Ismail ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Tissue Level ◽  
Leaf Sheath ◽  
Salt Sensitivity ◽  
Salt Tolerant ◽  
Basal Leaf ◽  
Rice Plants ◽  
Rice Leaf ◽  
Parenchyma Cells ◽  
Rice Genotypes

Salt sensitivity in rice plants is associated with the accumulated amount of Na+ and Cl– in shoots and, more significantly, in photosynthetic tissues. Therefore, salt removal ability at the leaf sheath level is an important mechanism of salt tolerance. In the present study we attempted to determine whether rice leaf sheaths excluded Cl– as well as Na+, and to identify the tissues that were involved in the removal ability of both ions. In two rice genotypes, salt-tolerant FL478 and -sensitive IR29, leaf sheaths excluded Na+ and Cl– under NaCl treatment as estimated using their sheath:blade ratios. The sheath:blade ratio of Na+ but not of Cl–, was increased by NaCl treatment. Under NaCl treatment, Na+ concentration was higher in the basal leaf sheath, whereas Cl– concentration was higher in the middle and tip parts. At the tissue level, fundamental parenchyma cells of leaf sheaths retained the highest amounts of Na and Cl when treated with high amount of NaCl. These results imply that the leaf sheath potentially functions to remove excess Na+ and Cl– from xylem vessels in different locations along the axis, with the fundamental parenchyma cells of leaf sheaths being involved in over-accumulation of both Na+ and Cl–.

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