scholarly journals Machine learning enabled phenotyping for GWAS and TWAS of WUE traits in 869 field-grown sorghum accessions

2020 ◽  
Author(s):  
John N. Ferguson ◽  
Samuel B. Fernandes ◽  
Brandon Monier ◽  
Nathan D. Miller ◽  
Dylan Allan ◽  
...  

ABSTRACTSorghum is a model C4 crop made experimentally tractable by extensive genomic and genetic resources. Biomass sorghum is also studied as a feedstock for biofuel and forage. Mechanistic modelling suggests that reducing stomatal conductance (gs) could improve sorghum intrinsic water use efficiency (iWUE) and biomass production. Phenotyping for discovery of genotype to phenotype associations remain bottlenecks in efforts to understand the mechanistic basis for natural variation in gs and iWUE. This study addressed multiple methodological limitations. Optical tomography and a novel machine learning tool were combined to measure stomatal density (SD). This was combined with rapid measurements of leaf photosynthetic gas exchange and specific leaf area (SLA). These traits were then the subject of genome-wide association study (GWAS) and transcriptome-wide association study (TWAS) across 869 field-grown biomass sorghum accessions. SD was correlated with plant height and biomass production. Plasticity in SD and SLA were interrelated with each other, and productivity, across wet versus dry growing seasons. Moderate-to-high heritability of traits studied across the large mapping population supported identification of associations between DNA sequence variation, or RNA transcript abundance, and trait variation. 394 unique genes underpinning variation in WUE-related traits are described with higher confidence because they were identified in multiple independent tests. This list was enriched in genes whose orthologs in Arabidopsis have functions related to stomatal or leaf development and leaf gas exchange. These advances in methodology and knowledge will aid efforts to improve the WUE of C4 crops.

Paleobiology ◽  
2011 ◽  
Vol 37 (2) ◽  
pp. 195-213 ◽  
Author(s):  
Taylor S. Feild ◽  
Garland R. Upchurch ◽  
David S. Chatelet ◽  
Timothy J. Brodribb ◽  
Kunsiri C. Grubbs ◽  
...  

The photosynthetic gas exchange capacities of early angiosperms remain enigmatic. Nevertheless, many hypotheses about the causes of early angiosperm success and how angiosperms influenced Mesozoic ecosystem function hinge on understanding the maximum capacity for early angiosperm metabolism. We applied structure-functional analyses of leaf veins and stomatal pore geometry to determine the hydraulic and diffusive gas exchange capacities of Early Cretaceous fossil leaves. All of the late Aptian—early Albian angiosperms measured possessed low vein density and low maximal stomatal pore area, indicating low leaf gas exchange capacities in comparison to modern ecologically dominant angiosperms. Gas exchange capacities for Early Cretaceous angiosperms were equivalent or lower than ferns and gymnosperms. Fossil leaf taxa from Aptian to Paleocene sediments previously identified as putative stem-lineages to Austrobaileyales and Chloranthales had the same gas exchange capacities and possibly leaf water relations of their living relatives. Our results provide fossil evidence for the hypothesis that high leaf gas exchange capacity is a derived feature of later angiosperm evolution. In addition, the leaf gas exchange functions of austrobaileyoid and chloranthoid fossils support the hypothesis that comparative research on the biology of living basal angiosperm lineages reveals genuine signals of Early Cretaceous angiosperm ecophysiology.


2016 ◽  
Vol 11 (6) ◽  
pp. 487-493
Author(s):  
Edineide Lima Barbosa Francisca ◽  
Feitosa De Lacerda Claudivan ◽  
De Oliveira Feitosa Hernandes ◽  
Jardelson Ferreira Francisco ◽  
Vieira Amorim Aiala ◽  
...  

2019 ◽  
Vol 40 (2) ◽  
pp. 198-214 ◽  
Author(s):  
Antti Tenkanen ◽  
Sarita Keski-Saari ◽  
Jarkko Salojärvi ◽  
Elina Oksanen ◽  
Markku Keinänen ◽  
...  

Abstract Due to its ubiquity across northern latitudes, silver birch (Betula pendula Roth) is an attractive model species for studying geographical trait variation and acclimation capacity. Six birch provenances from 60 to 67°N across Finland were grown in a common garden and studied for provenance and genotype variation. We looked for differences in height growth, photosynthetic gas exchange and chlorophyll content index (CCI) and compared the gas exchange of early and late leaves on short and long shoots, respectively. The provenances stratified into southern and northern groups. Northern provenances attained less height growth increment and had higher stomatal conductance (gs) and lower intrinsic water-use efficiency (WUE, Anet/gs) than southern provenances, whereas net photosynthesis (Anet) or CCI did not show clear grouping. Short shoot leaves had lower gs and higher WUE than long shoot leaves in all provenances, but there was no difference in Anet between shoot types. The separation of the provenances into two groups according to their physiological responses might reflect the evolutionary history of B. pendula. Latitudinal differences in gas exchange and water use traits can have plausible consequences for global carbon and water fluxes in a warming climate.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 127
Author(s):  
Richard M. Bastías ◽  
Pasquale Losciale ◽  
Camilla Chieco ◽  
Luca Corelli-Grappadelli

There is little information about the role of red and blue light on leaf morphology and physiology in fruit trees, and more studies have been developed in herbaceous plants grown under controlled light conditions. The objective of this research was to evaluate the effect of red and blue screens on morpho-anatomy and gas exchange in apple leaves grown under ambient sunlight conditions. Apple trees cv. Fuji were covered by 40% red and blue nets, leaving trees with 20% white net as control. Light relations (photosynthetic photon flux density, PPFD; red to far-red light ratio, R/FR and blue to red light ratio, B/R), morpho-anatomical features of the leaf (palisade to spongy mesophyll ratio, P/S, and stomata density, SD) and leaf gas exchange (net photosynthesis rate, An; stomatal conductance, gs; transpiration rate, E; and intrinsic water use efficiency, IWUE) were evaluated. Red and blue nets reduced 27% PPFD, reducing by 20% SD and 25% P/S compared to control, but without negative effects on An and gs. Blue net increased gs 21%, leading to the highest E and lowest IWUE by increment of B/R light proportion. These findings demonstrate the potential use of red and blue nets for differential modulation of apple leaf gas exchange through sunlight management under field conditions.


2014 ◽  
Vol 104 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Carlos Eduardo Aucique Perez ◽  
Fabrício Ávila Rodrigues ◽  
Wiler Ribas Moreira ◽  
Fábio Murilo DaMatta

This study investigated the effect of silicon (Si) on the photosynthetic gas exchange parameters (net CO2 assimilation rate [A], stomatal conductance to water vapor [gs], internal CO2 concentration [Ci], and transpiration rate [E]) and chlorophyll fluorescence a parameters (maximum quantum quenching [Fv/Fm and Fv′/Fm′], photochemical [qP] and nonphotochemical [NPQ] quenching coefficients, and electron transport rate [ETR]) in wheat plants grown in a nutrient solution containing 0 mM (–Si) or 2 mM (+Si) Si and noninoculated or inoculated with Pyricularia oryzae. Blast severity decreased due to higher foliar Si concentration. For the inoculated +Si plants, A, gs, and E were significantly higher in contrast to the inoculated –Si plants. For the inoculated +Si plants, significant differences of Fv/Fm between the –Si and +Si plants occurred at 48, 96, and 120 h after inoculation (hai) and at 72, 96, and 120 hai for Fv′/Fm′. The Fv/Fm and Fv′/Fm′, in addition to total chlorophyll concentration (a + b) and the chlorophyll a/b ratio, significantly decreased in the –Si plants compared with the +Si plants. Significant differences between the –Si and +Si inoculated plants occurred for qP, NPQ, and ETR. The supply of Si contributed to decrease blast severity in addition to improving gas exchange performance and causing less dysfunction at the photochemical level.


2020 ◽  
Vol 16 (4) ◽  
pp. 1509-1521
Author(s):  
Tammo Reichgelt ◽  
William J. D'Andrea ◽  
Ailín del C. Valdivia-McCarthy ◽  
Bethany R. S. Fox ◽  
Jennifer M. Bannister ◽  
...  

Abstract. Rising atmospheric CO2 is expected to increase global temperatures, plant water-use efficiency, and carbon storage in the terrestrial biosphere. A CO2 fertilization effect on terrestrial vegetation is predicted to cause global greening as the potential ecospace for forests expands. However, leaf-level fertilization effects, such as increased productivity and water-use efficiency, have not been documented from fossil leaves in periods of heightened atmospheric CO2. Here, we use leaf gas-exchange modeling on a well-preserved fossil flora from early Miocene New Zealand, as well as two previously published tropical floras from the same time period, to reconstruct atmospheric CO2, leaf-level productivity, and intrinsic water-use efficiency. Leaf gas-exchange rates reconstructed from early Miocene fossils, which grew at southern temperate and tropical latitudes when global average temperatures were 5–6 ∘C higher than today, reveal that atmospheric CO2 was ∼450–550 ppm. Early Miocene CO2 was similar to projected values for 2040 CE and is consistent with an Earth system sensitivity of 3–7 ∘C to a doubling of CO2. The Southern Hemisphere temperate leaves had higher reconstructed productivity than modern analogs, likely due to a longer growing season. This higher productivity was presumably mirrored at northern temperate latitudes as well, where a greater availability of landmass would have led to increased carbon storage in forest biomass relative to today. Intrinsic water-use efficiency of both temperate and tropical forest trees was high, toward the upper limit of the range for modern trees, which likely expanded the habitable range in regions that could not support forests with high moisture demands under lower atmospheric CO2. Overall, early Miocene elevated atmospheric CO2 sustained globally higher temperatures, and our results provide the first empirical evidence of concomitant enhanced intrinsic water-use efficiency, indicating a forest fertilization effect.


Irriga ◽  
2016 ◽  
Vol 21 (4) ◽  
pp. 806-816
Author(s):  
Francisco Rodolfo Junior ◽  
Walter Quadros Ribeiro Junior ◽  
Maria Lucrécia Gerosa Ramos ◽  
Omar Cruz Rocha ◽  
Fábio Pedro Silva Batista ◽  
...  

RESPOSTAS FISIOLÓGICAS EM VARIEDADES DE CANA SOCA SUBMETIDAS AO DÉFICIT HÍDRICO              FRANCISCO RODOLFO JUNIOR1; WALTER QUADROS RIBEIRO JUNIOR2; MARIA LUCRÉCIA GEROSA RAMOS3; OMAR CRUZ ROCHA2; FÁBIO PEDRO SILVA BATISTA4 E CRISTIANE ANDRÉA DE LIMA2 1 Universidade Federal do Piauí-CPCE, BR 135, km 03, Planalto Horizonte, CEP 64900-000, Bom Jesus, Piauí, Brasil, [email protected];2Embrapa Cerrados, BR 020 Km 18, Planaltina - DF, CEP 73310-970, [email protected], [email protected], [email protected];3Universidade de Brasília/FAV, Instituto Central de Ciências, Sul (ICC-Sul), CEP 70.910-970, [email protected];4Doutorando do Programa de Pós-Graduação em Agronomia, Universidade de Brasília/FAV, ICC-Sul, CEP 70.910-970, [email protected];  1 RESUMO A baixa disponibilidade hídrica afeta negativamente os cultivos agrícolas e é a principal causa da redução da produtividade no setor sucroalcooleiro no Brasil. O objetivo deste trabalho foi caracterizar fisiologicamente as variedades da cana-de-açúcar, submetidas a diferentes regimes hídricos. O experimento foi conduzido em uma área de 0,36 hectares, localizada na Embrapa Cerrados, próxima a Planaltina-DF. O delineamento foi em blocos ao acaso com três repetições em parcelas subdivididas no tempo, com três variedades (RB855156, RB835486 e RB867515-parcela), ausência e presença da irrigação (irrigado e sequeiro - subparcela) e quatro coletas de dados no tempo (100; 150; 200 e 250 dias após o corte) que foram as subsubparcelas. Foram avaliadas as seguintes características fisiológicas: prolina livre a folha, trocas gasosas: transpiração (E), condutância estomática (gs), fotossíntese líquida (A), eficiência intrínseca do uso da água (EIUA), eficiência da carboxilação (EC), clorofila tipo a (Clo-a) e clorofila total (Clo-a+b). As variedades de cana-de-açúcar cultivadas em sistema de sequeiro apresentaram aumento na concentração foliar de prolina e EIUA, e redução de E, gs, A, EC, Clo-a e Clo-a+b. Palavras-Chave: Saccharum spp. L.; estresse abiótico; prolina; trocas gasosas.  RODOLFO JUNIOR, F.; RIBEIRO JUNIOR, W. Q.; RAMOS, M. L. G.; ROCHA, O. C.; BATISTA, F. P. S.; LIMA, C. A.PHYSIOLOGICAL RESPONSES IN VARIETIES OF RATOON SUGARCANE SUBMITTED TO WATER DEFICIT  2 ABSTRACT Low water supply affects negatively agricultural crops and is the main cause of reduced productivity in the sugar and ethanol industry in Brazil. The objective of this paper was to physiologically characterize the varieties of sugar cane under different water regimes. The experiment was conducted in an area of 0.36 hectares, located in Embrapa Cerrado, near Planaltina-DF. The design was randomized with three replicates in parcels subdivided in time, with three varieties (RB855156, RB835486 and RB867515-plots), with absence and presence of irrigation (irrigated and rainfed- subplots) and four data collections over time  (100; 150; 200 and 250 days after harvest), that formed the subsubplots. The following physiological characteristics were assessed: free proline in leaves, leaf gas exchange: transpiration (E), stomatal conductance (gs), net photosynthesis (A), intrinsic water use efficiency (EIUA), efficiency of carboxylation (EC), chlorophyll type a (Clo-a) e total chlorophyll (Clo-a+b). The varieties of sugarcane cultivated in rainfed system presented increase in leaf concentration of proline and EIUA, and reduced E, gs, A, EC, Cloa, Clo-a+b. Keywords: Saccharum spp. L.; abiotic stress; proline; gas exchange.


2015 ◽  
Vol 105 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Maria Bianney Bermúdez-Cardona ◽  
João Américo Wordell Filho ◽  
Fabrício Ávila Rodrigues

This study investigated the effect of macrospora leaf spot (MLS), caused by Stenocarpella macrospora, on photosynthetic gas exchange parameters and chlorophyll a fluorescence parameters determined in leaves of plants from two maize cultivars (‘ECVSCS155’ and ‘HIB 32R48H’) susceptible and highly susceptible, respectively, to S. macrospora. MLS severity was significantly lower in the leaves of plants from ECVSCS155 relative to the leaves of plants from HIB 32R48H. In both cultivars, net CO2 assimilation rate, stomatal conductance, and transpiration rate significantly decreased, while the internal to ambient CO2 concentration ratio increased in inoculated plants relative to noninoculated plants. The initial fluorescence and nonphotochemical quenching significantly increased in inoculated plants of ECVSCS155 and HIB 32R48H, respectively, relative to noninoculated plants. The maximum fluorescence, maximum PSII quantum efficiency, coefficient for photochemical quenching, and electron transport rate significantly decreased in inoculated plants relative to noninoculated plants. For both cultivars, concentrations of total chlorophyll (Chl) (a + b) and carotenoids and the Chl a/b ratio significantly decreased in inoculated plants relative to noninoculated plants. In conclusion, the results from the present study demonstrate, for the first time, that photosynthesis in the leaves of maize plants is dramatically affected during the infection process of S. macrospora, and impacts are primarily associated with limitations of a diffusive and biochemical nature.


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