scholarly journals Rubisco activity, electron transport rate, and leaf features drive high photosynthesis rate in the selected wild rice

2019 ◽  
Author(s):  
Jyotirmaya Mathan ◽  
Anuradha Singh ◽  
Vikram Jathar ◽  
Aashish Ranjan
Keyword(s):  
Electron Transport ◽  
Wild Rice ◽  
Electron Transport Rate ◽  
Transport Rate ◽  
Leaf Photosynthesis ◽  
Cultivated Rice ◽  
Rubisco Activity ◽  
Rice Varieties ◽  
Mesophyll Cells ◽  
Wild Rice Species

AbstractThe importance of increasing photosynthetic efficiency for sustainable crop yield increases to feed the growing world population is well recognized. The natural genetic variation for leaf photosynthesis in crop plants is largely unexploited for increasing genetic yield potential. The genus Oryza, including cultivated rice and wild relatives, offers tremendous genetic variability to explore photosynthetic differences, and underlying biochemical, photochemical, and developmental basis. We quantified leaf photosynthesis and related physiological parameters for six cultivated and three wild rice genotypes, and identified photosynthetically efficient wild rice species. Fitting A/Ci curves followed by experimental validation showed that the leaf photosynthesis in cultivated rice varieties, IR64 and Nipponbare, was limited due to Rubisco activity and electron transport rate, compared to photosynthetically efficient wild rice species, Oryza australiensis and Oryza latifolia. The selected wild rice species with high leaf photosynthesis per unit area had striking anatomical features, such as larger mesophyll cells with more chloroplasts, larger and closer veins, and fewer mesophyll cells between two consecutive veins. Our results show the existence of desirable variations in Rubisco activity, electron transport rate, and mesophyll and vein features in the rice system itself that could possibly be targeted for increasing the photosynthetic efficiency of cultivated rice varieties.HighlightDistinct leaf biochemical, photochemical, and developmental features contribute to efficient photosynthesis in the selected wild rice that could potentially be exploited for increasing rice leaf photosynthesis.

Whole grain morphology of Australian rice species

2009 ◽  
Vol 8 (1) ◽  
pp. 74-81 ◽  
Author(s):  
S. Kasem ◽  
D. L. E. Waters ◽  
N. Rice ◽  
F. M. Shapter ◽  
R. J. Henry
Keyword(s):  
Wild Rice ◽  
Grain Morphology ◽  
Whole Grain ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Wild Rice Species ◽  
Breeding Programmes ◽  
Standard Classification ◽  
Novel Alleles ◽  
Grain Colour

The grain morphology of 17 wild rice relatives were studied by light and scanning electron microscopy and compared to two cultivated rice varieties (Oryza sativa cv. Nipponbare and O. sativa cv. Teqing). Observations were made of the grain colour, size and shape. Grains from wild rice species exhibited a variety of colours that have potential aesthetic and nutritional value. The grains of these species exhibited a wide array of sizes and shapes, but still fell within the standard classification scale that rice breeders use for routine breeding evaluation. These results highlight the potential of these species as whole grain foods or as sources of novel alleles in conventional rice breeding programmes.

scholarly journals Enhancement of Rice Leaf Photosynthesis by Crossing between Cultivated Rice,Oryza sativaand Wild Rice Species,Oryza rufipogon

2004 ◽  
Vol 7 (3) ◽  
pp. 252-259 ◽  
Author(s):  
Chisato Masumoto ◽  
Takashige Ishii ◽  
Sono Kataoka ◽  
Tomoko Hatanaka ◽  
Naotsugu Uchida
Keyword(s):  
Wild Rice ◽  
Oryza Rufipogon ◽  
Leaf Photosynthesis ◽  
Cultivated Rice ◽  
Rice Leaf ◽  
Wild Rice Species

scholarly journals Spesies Padi Liar (Oryza sp.) sebagai Sumber Gen Ketahanan Cekaman Abiotik dan Biotik pada Padi Budidaya

2017 ◽  
Vol 35 (4) ◽  
pp. 197
Author(s):  
Tintin Suhartini
Keyword(s):  
Resistance Gene ◽  
Resistance Genes ◽  
Abiotic Stresses ◽  
Wild Rice ◽  
Brown Planthopper ◽  
Cultivated Rice ◽  
Biotic And Abiotic Stresses ◽  
Rice Varieties ◽  
Wild Rice Species ◽  
Oryza Meyeriana

<p>ABSTRACT<br />Wild rice species could be used  for improvement of rice varieties because they have a good character for resistance to biotic and abiotic stresses. Some of Indonesian wild rice species are Oryza meyeriana, O. granulata, O. longiglumis, O. officinalis, O. ridleyi, O. rufipogon and O. schlechteri. IRRI has a collection of 2,500 accesions of wild rice and 18 species were collected in ICABIOGRAD, Bogor. Some species of wild rice are known to have resistance genes to biotic and abiotic stresses. A number of<br />accessions of O.  officinalis contained resistance gene to brown planthopper, blast disease, bacterial leaf blight (BLB) and sheath rot. One of the species that has resistance to pests and diseases is O. minuta. The resistance to tungro virus occurs in O. punctata. Tolerance to drought, Al and Fe toxicities occurs in wild rice species of O. sativa genome AA group. Resistance genes from wild rice species can be inserted into cultivated rice through conventional techniques in combination with biotechnology, while gene transfer and gene detection from wild rice to cultivated rice can be done through cross breeding, molecular markers, backcrossing and embryo rescue. The success of introgression of resistance genes from wild rice species to cultivated rice will increase genetic diversity of rice. As an example O. minuta has been implemented in introgression of BLB resistance gene on IR64. Introgression of O. nivara gene in IRRI had improved some superior rice varieties in Indonesia, namely IR30, IR32, IR34, IR36 and IR38, which were tolerant to brown planthopper, dwarf virus and bacterial leaf blight. Oryza rufipogon wich has BLB and blast resistance gene has been used for improvement of new varieties Inpari Blas and Inpari HDB which were released in 2013.<br />Keywords: Oryza spp., varietal improvement, resistance genes, biotic stresses, abiotic stresses</p><p>Abstrak</p><p>Spesies padi liar dapat dimanfaatkan dalam perakitan varietas unggul karena memiliki gen ketahanan terhadap cekaman biotik dan abiotik. Spesies padi liar yang ada di Indonesia adalah Oryza meyeriana, O. granulata, O. longiglumis, O. officinalis, O. ridleyi, O. rufipogon, dan O. schlechteri. IRRI memiliki koleksi 2.500 aksesi padi liar dan 18 spesies dikoleksi di BB Biogen. Sejumlah aksesi O. officinalis memiliki gen ketahanan terhadap wereng coklat, penyakit blas, hawar daun bakteri (HDB), dan busuk pelepah. Salah satu spesies yang memiliki ketahanan terhadap hama-penyakit tersebut adalah O. minuta. Ketahanan terhadap virus tungro terdapat pada O. punctata. Toleransi terhadap kekeringan, keracunan Al, dan Fe terdapat pada spesies padi liar kelompok O. sativa genom AA. Gen ketahanan dari spesies padi liar dapat dimasukkan (introgresi) ke dalam padi budi daya melalui teknik konvensional yang dikombinasikan dengan bioteknologi, sementara transfer gen dapat melalui persilangan, marka molekuler, silang balik, dan penyelamatan embrio. Keberhasilan introgresi gen ketahanan dari spesies padi liar ke padi budi daya akan meningkatkan keragaman genetik tanaman. Spesies padi liar O. minuta telah dimanfaatkan dalam introgresi gen ketahanan HDB pada varietas IR64. Introgresi gen asal O. nivara di IRRI menambah varietas unggul di Indonesia, yaitu IR30, IR32, IR34, IR36, dan IR38, yang toleran terhadap wereng coklat, virus kerdil rumput, dan HDB. Spesies padi liar O. rufipogon yang memiliki gen ketahanan HDB dan blas telah digunakan dalam pembentukan varietas unggul baru Inpari HDB dan Inpari Blas yang dilepas pada 2013.<br /><br /></p>

scholarly journals Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species

2001 ◽  
Vol 67 (11) ◽  
pp. 5285-5293 ◽  
Author(s):  
Adel Elbeltagy ◽  
Kiyo Nishioka ◽  
Tadashi Sato ◽  
Hisa Suzuki ◽  
Bin Ye ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Wild Rice ◽  
Fluorescent Protein ◽  
In Planta ◽  
Cultivated Rice ◽  
Phenotypic Properties ◽  
Rice Varieties ◽  
Bacterial Populations ◽  
Rdna Sequences ◽  
Wild Rice Species

ABSTRACT Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum,Ideonella, Enterobacter, andAzospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2gas incorporation assays. Therefore, we conclude thatHerbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis.

scholarly journals Updating the steady state model of C4 photosynthesis

2021 ◽  
Author(s):  
Susanne von Caemmerer
Keyword(s):  
Steady State ◽  
Electron Transport ◽  
Electron Transport Rate ◽  
Transport Rate ◽  
Initial Slope ◽  
Carboxylase Activity ◽  
Quantitative Correlation ◽  
Steady State Model ◽  
State Models

AbstractC4 plants play a key role in world agriculture. For example, C4 crops such as maize and sorghum are major contributors to both first and third world food production and the C4 grasses sugarcane; miscanthus and switchgrass are major plant sources of bioenergy. In the challenge to manipulate and enhance C4 photosynthesis, steady state models of leaf photosynthesis provide and important tool for gas exchange analysis and thought experiments that can explore photosynthetic pathway changes. Here the C4 photosynthetic model by von Caemmerer and Furbank (1999) has been updated with new kinetic parameterisation and temperature dependencies added. The parameterisation was derived from experiments on the C4 monocot, Setaria viridis, which for the first time provides a cohesive parametrisation. Mesophyll conductance and its temperature dependence have also been included, as this is an important step in the quantitative correlation between the initial slope of the CO2 response curve of CO2 assimilation and in vitro PEP carboxylase activity. Furthermore, the equations for chloroplast electron transport have been updated to include cyclic electron transport flow and equations have been added to calculate electron transport rate from measured CO2 assimilation rates.HighlightThe C4 photosynthesis model by von Caemmerer and Furbank (1999) has been updated. It now includes temperature dependencies and equations to calculate electron transport rate from measured CO2 assimilation rates.

scholarly journals Mefenpyr-diethyl as a safener for haloxyfop-methyl in bahiagrass

2021 ◽  
Author(s):  
Roque de Carvalho Dias ◽  
Leandro Bianchi ◽  
Vitor Muller Anunciato ◽  
Leandro Tropaldi ◽  
Paulo Vinicius da Silva ◽  
...  
Keyword(s):  
Electron Transport ◽  
Protective Effect ◽  
Plant Height ◽  
Electron Transport Rate ◽  
Transport Rate ◽  
Low Doses ◽  
Protective Response ◽  
Randomized Design ◽  
Dry Biomass ◽  
Completely Randomized Design

Abstract Mefenpyr-diethyl is a foliar-acting safener of the pyrazoline chemical group, and after its absorption, the metabolization and detoxification of herbicides occur in treated plants. Studies have demonstrated the protective effect of this safener for the herbicide fenoxaprop-P-ethyl in grass. Thus, this work aimed to evaluate whether a tank mixture of mefenpyr-diethyl has a protective response to haloxyfop-methyl in non-perennial bahiagrass. The experiment had a completely randomized design and was carried out in a greenhouse, using five replications with a 10x2 factorial scheme and ten doses of haloxyfop-methyl (0.00, 0.24, 0.49, 0.97, 1.95, 3.90, 7.79, 15.59, 31.28, and 62.35 g a.i. ha-1) in the presence or absence of a tank mixture of mefenpyr-diethyl (50 g a.i. ha-1). Phytotoxicity and electron transport rate (ETR) were evaluated at 7, 14, 21, and 28 days after application (DAA), in addition to plant height and dry biomass at 28 DAA. In general, phytotoxicity increased due to the higher levels of the herbicide haloxyfop-methyl. The application of mefenpyr-diethyl, in turn, provided lower levels of phytotoxicity, as well as lower reductions in ETR, height, and dry biomass when compared to untreated plants. These results show the safener action of a tank mixture of mefenpyr-diethyl on low doses of haloxyfop-methyl in non-perennial bahiagrass.

scholarly journals Physiological Characteristics of Photosynthesis in Yellow-Green, Green and Dark-Green Chinese Kale (Brassica oleracea L. var. alboglabra Musil.) under Varying Light Intensities

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 960
Author(s):  
Kuan-Hung Lin ◽  
Feng-Chi Shih ◽  
Meng-Yuan Huang ◽  
Jen-Hsien Weng
Keyword(s):  
Electron Transport ◽  
Energy Dissipation ◽  
Light Intensity ◽  
Thermal Energy ◽  
Electron Transport Rate ◽  
Transport Rate ◽  
Physiological Characteristics ◽  
Chinese Kale ◽  
Thermal Energy Dissipation ◽  
Dark Green

The objective of this work was to study physiological characteristics and photosynthetic apparatus in differentially pigmented leaves of three Chinese kale cultivars. Chlorophyll (Chl) fluorescence and photochemical reflectance index (PRI) measurements in green, yellow-green, and dark-green cultivars in response to varying light intensities. As light intensity increased from 200 to 2000 photosynthetic photon flux density (PPFD), fraction of light absorbed in photosystem (PS) II and PRI values in all plants were strongly lowered, but fraction of light absorbed in PSII dissipated via thermal energy dissipation and non-photochemical quenching (NPQ) values in all plants wereremarkably elevated.When plants were exposed to 200 PPFD, the values of fraction of light absorbed in PSII, utilized in photosynthetic electron transport(p), andfraction of light absorbed excitation energy in PSII dissipated via thermal energy dissipation (D), remained stable regardless of the changes in levels of Chla + b. Under 800 and 1200 PPFD, the values of p and electron transport rate (ETR) decreased, but D and NPQ increased as Chla + bcontent decreased, suggesting that decrease inChla + bcontent led to lower PSII efficiency and it became necessary to increase dissipate excess energy. On the contrary, in 2000 PPFD, leaves with lower Chla + bcontent had relatively higher p and electron transport rate (ETR) values and lower D level, as well as tended to increase more in NPQ but decrease more in PRI values. The consistent relations between PRI and NPQ suggest that NPQ is mainly consisted ofthe xanthophyll cycle-dependentenergy quenching.Yellow-green cultivar showed lower Chla + bcontent but high carotenoids/Chla + b ratio and had high light protection ability under high PPFD. The precise management of photosynthetic parameters in response to light intensity can maximize the growth and development of Chinese kale plants.

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