scholarly journals Role of Triose Phosphate Utilization in photosynthetic response of rice to variable carbon dioxide levels and plant source-sink relations

2019 ◽  
Author(s):  
Denis Fabre ◽  
Xinyou Yin ◽  
Michael Dingkuhn ◽  
Anne Clément-Vidal ◽  
Sandrine Roques ◽  
...  
Keyword(s):  
Indica Rice ◽  
Flag Leaf ◽  
Rice Cultivar ◽  
Photosynthetic Parameters ◽  
Response Curves ◽  
Crop Models ◽  
Triose Phosphate ◽  
Sink Limitation ◽  
Carbon Dioxide Levels ◽  
Source Sink

AbstractThis study aimed to understand the physiological bases of rice photosynthesis response to C source-sink imbalances, with focus on dynamics of the photosynthetic parameter TPU (Triose Phosphate Utilization). A dedicated experiment was replicated twice on IR64 indica rice cultivar in controlled environments. Plants were grown under the current ambient CO2 concentration until heading, thereafter, two CO2 treatments (400 and 800 μmol mol−1) were compared in the presence and absence of a panicle pruning treatment modifying the C sink. At two weeks after heading, photosynthetic parameters derived from CO2 response curves, and nonstructural carbohydrate content of flag leaf and internodes were measured 3-4 times of day. Spikelet number per panicle and flag leaf area on the main culm were recorded. Net C assimilation and TPU decreased progressively after midday in panicle-pruned plants, especially under 800 μmol mol−1. This TPU reduction was explained by sucrose accumulation in the flag leaf resulting from the sink limitation. It is suggested that TPU is involved in rice photosynthesis regulation under elevated CO2 conditions, and that sink limitation effects should be considered in crop models.HighlightThis study provide new insights in the effect of C source-sink relationships on rice photosynthesis. TPU should be considered in photosynthesis studies under severe source-sink imbalance at elevated CO2.

scholarly journals Is triose phosphate utilization involved in the feedback inhibition of photosynthesis in rice under conditions of sink limitation?

2019 ◽  
Vol 70 (20) ◽  
pp. 5773-5785 ◽  
Author(s):  
Denis Fabre ◽  
Xinyou Yin ◽  
Michael Dingkuhn ◽  
Anne Clément-Vidal ◽  
Sandrine Roques ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Feedback Inhibition ◽  
Triose Phosphate ◽  
Sink Limitation ◽  
Source Sink ◽  
Regulation Of Photosynthesis

Triose phosphate utilization is involved in the regulation of photosynthesis under elevated CO2 conditions, and it should be considered in photosynthesis studies under severe source–sink imbalance at elevated CO2.

Partitioning of 13C-labelled photosynthate varies with growth stage andpanicle size in high-yielding rice

2004 ◽  
Vol 31 (2) ◽  
pp. 131 ◽  
Author(s):  
Pravat K. Mohapatra ◽  
Yasuyuki Masamoto ◽  
Satoshi Morita ◽  
Junichi Takanashi ◽  
Tsuneo Kato ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Flag Leaf ◽  
Source Area ◽  
Grain Filling ◽  
Rice Cultivar ◽  
Japonica Rice ◽  
Heavy Carbon ◽  
Heavy Carbon Isotope ◽  
Source Sink ◽  
Developing Grains

A super-high-yielding rice (Oryza sativa L.) cultivar, Takanari, and a traditional japonica rice cultivar, Nakateshinsenbon, were grown under field conditions to compare partitioning of 13C-labelled photosynthate to different plant organs during the period of reproductive development. The flag leaf and the two leaves immediately below it on the main culm were exposed individually to 13CO2 and the movement of the heavy carbon isotope to grains, hull, panicle branches and vegetative parts of plant was assessed. Also, the effect of a reduction of sink size on the partitioning of 13C to different organs was studied by removing some of the primary branches of the panicle. 13C taken up by the three leaves in the post-heading period, moved mostly to the grains and hull of the panicle. At this stage, the uppermost three leaves and the panicle consisted of a single source–sink unit. Partitioning of 13C to the rest of the vegetative structures of the plant was minimal. In the case of Nakateshinsenbon, the flag leaf supplied most of the carbon assimilates for the grains and contributions from the other two leaves were much smaller. However, in Takanari, the contribution of 13C to grains from the second leaf was equivalent to that of the flag leaf. In Takanari, removal of more than one third of the primary branches of the panicle significantly reduced partitioning from the third leaf of the culm, but partitioning from the flag leaf was not significantly changed. In contrast, branch removal treatment significantly depressed transport of carbon assimilates from the flag leaf in Nakateshinsenbon. The obligatory nature of the source–sink relationship in rice is discussed. It is concluded that in lower-yielding traditional rice, photosynthesis in the flag leaf supplies carbon assimilates to the developing grains. But in the super-yielding rice Takanari, the main source area is extended to include the two leaves below the flag leaf so as to sustain an extra large panicle. Even greater grain-filling is possible in super-yielding rice, if the source area is increased further.

scholarly journals Are crop and detailed physiological models equally "mechanistic" for predicting the genetic variability of whole plant behaviour? - the nexus between mechanisms and adaptive strategies

2020 ◽  
Author(s):  
F Tardieu ◽  
I S C Granato ◽  
E J Van Oosterom ◽  
B Parent ◽  
G L Hammer
Keyword(s):  
Genetic Variability ◽  
Growth And Yield ◽  
Specific Response ◽  
Response Curves ◽  
Evaporative Demand ◽  
Physiological Mechanisms ◽  
Physiological Models ◽  
Crop Models ◽  
Whole Plant ◽  
Developmental Traits

Abstract Tailoring genotypes for the variety of environmental scenarios associated with climate change requires modelling of the genetic variability of adaptation mechanisms to environmental cues. A large number of physiological mechanisms have been described and modelled, e.g. at transcript, metabolic or hormonal levels, but they remain to be assembled into whole-plant and canopy models. A 'bottom-up' approach combining physiological mechanisms leads to a near-infinite number of combinations and to an unmanageable number of parameters, so more parsimonious approaches are required. We propose that natural selection has constrained the large diversity of mechanisms into consistent strategies, in such a way that not all combinations of mechanisms are possible. These constraints, and resulting feedbacks, result in integrative 'metamechanisms', e.g. response curves of traits to environmental conditions, measurable via high throughput phenotyping, and resulting in robust and stable equations with heritable genotype-dependent parameters. Examples are provided for the responses of developmental traits to temperature, for the response of growth and yield to water deficit and evaporative demand, and for the response of tillering to light and temperature. In these examples, it was inoperative to combine upstream mechanisms into whole-plant mechanisms, whereas the evolutionary constraints on the combinations of physiological mechanisms renders possible the use of genotype-specific response curves at plant or canopy levels. These can be used for a new generation of crop models capable of simulating the behavior of thousands of genotypes. This has significant consequences for plant modelling and its use in genetics and breeding.

scholarly journals Improved Method for Anther Culture of an Indica Rice Cultivar of Thailand

2000 ◽  
Vol 3 (3) ◽  
pp. 254-256 ◽  
Author(s):  
Prapa Sripichitt ◽  
Takashi Ozawa ◽  
Motoyasu Otani ◽  
Takiko Shimada
Keyword(s):  
Anther Culture ◽  
Indica Rice ◽  
Rice Cultivar ◽  
Improved Method ◽  
Indica Rice Cultivar

Physiological characterization of introgression lines derived from an indica rice cultivar, IR64, adapted to drought and water-saving irrigation

2011 ◽  
Vol 123 (2) ◽  
pp. 130-138 ◽  
Author(s):  
Yoichiro Kato ◽  
Amelia Henry ◽  
Daisuke Fujita ◽  
Keisuke Katsura ◽  
Nobuya Kobayashi ◽  
...  
Keyword(s):  
Indica Rice ◽  
Rice Cultivar ◽  
Water Saving ◽  
Introgression Lines ◽  
Physiological Characterization ◽  
Indica Rice Cultivar

Breeding and application of Jiafuzhan, a new elite early indica rice cultivar in China

2007 ◽  
Vol 2 (2) ◽  
pp. 144-150
Author(s):  
Houcong Wang ◽  
Huakang Huang ◽  
Simi Qiu ◽  
Shi Zhang ◽  
Yashun Fang ◽  
...  
Keyword(s):  
Indica Rice ◽  
Rice Cultivar ◽  
Early Indica Rice ◽  
Indica Rice Cultivar

scholarly journals LMM24 Encodes Receptor-Like Cytoplasmic Kinase 109, Which Regulates Cell Death and Defense Responses in Rice

2019 ◽  
Vol 20 (13) ◽  
pp. 3243 ◽  
Author(s):  
Yue Zhang ◽  
Qunen Liu ◽  
Yingxin Zhang ◽  
Yuyu Chen ◽  
Ning Yu ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Indica Rice ◽  
Defense Responses ◽  
Rice Cultivar ◽  
Histochemical Staining ◽  
Lesion Mimic ◽  
Ros Accumulation ◽  
Mutant Pool ◽  
Defense Response Genes

Lesion mimic mutants are excellent models for research on molecular mechanisms of cell death and defense responses in rice. We identified a new rice lesion mimic mutant lmm24 from a mutant pool of indica rice cultivar “ZhongHui8015”. The LMM24 gene was identified by MutMap, and LMM24 was confirmed as a receptor-like cytoplasmic kinase 109 by amino acid sequence analysis. The lmm24 mutant displayed dark brown lesions in leaves and growth retardation that were not observed in wild-type ZH8015. The results of histochemical staining and TUNEL assays showed enhanced ROS accumulation and cell death in lmm24. Chloroplast degradation was observed in lmm24 leaves, with decreased expression of photosynthesis-related genes and increased expression of the senescence-induced STAYGREEN (SGR) gene and other senescence-associated genes. Furthermore, lmm24 exhibited enhanced resistance to rice blast fungus Magnaporthe oryzae (M. oryzae) and up-regulation of defense response genes. Our data demonstrate that LMM24 regulates cell death and defense responses in rice.

scholarly journals Estimating Organ Contribution to Grain Filling and Potential for Source Upregulation in Wheat Cultivars with a Contrasting Source–Sink Balance

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1527
Author(s):  
Carolina Rivera-Amado ◽  
Gemma Molero ◽  
Eliseo Trujillo-Negrellos ◽  
Matthew Reynolds ◽  
John Foulkes
Keyword(s):  
Grain Growth ◽  
Photosynthetic Rate ◽  
Grain Filling ◽  
Leaf Sheath ◽  
Grain Weight ◽  
Yield Potential ◽  
Wheat Cultivars ◽  
Sink Limitation ◽  
Source Sink ◽  
Source And Sink

Grain filling may be limited by the joint source and sink capacity in modern wheat cultivars, indicating a need to research the co-limitation of yield by both photosynthesis and the number and potential size of grains. The extent to which the post-anthesis source may be limiting final grain size can be estimated by partial degraining of spikes, while defoliation and shading treatments can be useful to estimate if any excess photosynthetic capacity exists. In the current study, degraining was applied to a set of 26 elite spring wheat cultivars from the International Maize and Wheat Improvement Center (CIMMYT)’s core germplasm (CIMCOG) panel, while lamina defoliation and shading through stem-and-leaf-sheath covering treatments were applied to a subset of the same cultivars. Responses to source treatments in grain weight, pre-anthesis reserve contribution to grain weight, dry-matter translocation efficiency, and flag-leaf and spike photosynthetic rate were measured and compared to an unmanipulated control treatment. Grain weight responses to degraining among cultivars ranged from no response to increases of 28%, suggesting a range of responses from sink limitation, to probable source and sink co-limitation of grain growth. Grain weight’s response to degraining increased linearly with the years of cultivar release from 1966 to 2009, indicating that the current highest yield potential CIMMYT spring wheats have a co-limitation of grain growth by source and sink. This may have been due to an increase in grain sink strength with years of cultivar release with no commensurate increase in post-anthesis source capacity. The relatively low decreases in grain weight with defoliation compared to decreases in light interception by defoliation indicated that sink limitation was still likely predominating in the cultivars with co-limitation. The stem-and-leaf-sheath covering treatment decreased grain weight by nearly 10%, indicating that stem-and-leafsheath photosynthesis plays a key role in grain growth during grain filling. In addition, pre-anthesis reserve contribution to grain weight was increased by ca. 50% in response to lamina defoliation. Our results showed that increasing the post-anthesis source capacity, through increases in stem-and-leaf-sheath photosynthetic rate during grain filling and pre-anthesis reserve contribution to grain weight, is an important objective in enhancing yield potential in wheat through maintaining a source–sink balance.

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