Paraheliotropism in two Phaseolus species: combined effects of photon flux density and pulvinus temperature, and consequences for leaf gas exchange

Bielenberg, Douglas G.; Miller, Jennifer D.; Berg, Virginia

doi:10.1016/s0098-8472(02)00062-x

Cited by 34 publications

(34 citation statements)

References 30 publications

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“…Its ecophysiological significance consists in the light interception maximization and the carbon gain enhancement, provided that the leaf has the physiological capacity to utilize high irradiances (Forseth & Ehleringer, 1983). Paraheliotropism is the ability of leaves to maintain the leaf lamina parallel to the sun's direct rays, and this phenomenon is often associated with plant efforts to reduce the negative effects of water stress (Kao & Forseth, 1992), UVB photoinhibition (Bawhey et al, 2003), and high leaf temperature (Bielenberg et al, 2003), generally acting on transpiration and stomatal conductance (Isoda & Shah, 2006). Photosynthetic photon flux density (PPFD) (Fu & Ehleringer, 1991), leaf temperature (Bielenberg et al, 2003), soil water potential, leaf water potential (Rosa et al, 1991), and nitrogen availability (Kao & Forseth, 1992) also can affect leaf positioning.…”

Section: Introductionmentioning

confidence: 99%

Heliotropic responses of soybean cultivars at three phenological stages and under two water regimes

Rakocevic

Neumaier

Oliveira

et al. 2010

Pesq. agropec. bras.

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-The objectives of this work were to determine the heliotropic movements of the upper trifoliates for two soybean cultivars, BR 16 and Embrapa 48, during a daily cycle, in three phenological stages and two water regimes, and to estimate the impact of irrigation and daily leaflet movements on agronomic characteristics and grain yield. Heliotropic movements were studied in three phenological stages: V4-V6, V7-V10, and R5 in irrigated and non-irrigated plots. For each stage, the leaflet elevation and azimuth were measured hourly. Under a low (V4-V6 stage) and mid (V7-V10 stage) leaf area index (LAI) the diaheliotropism was slightly more frequent and intensive in non-irrigated than in irrigated plants, only at early morning and late afternoon hours. At R5 stage (high LAI) the paraheliotropism of superior trifoliates was predominant and more intensive in non-irrigated plants. The heliotropic movements are correlated to carbon gain, but not to environment (light intensity or temperature), for measurements at 11h. 'Embrapa 48' expresses greater paraheliotropism than 'BR 16' at high LAI, while 'BR 16' displays lower heliotropic plasticity under irrigation. In spite of significant heliotropic differences, genotype and water availability treatments did not influence the final grain yield.Index terms: Glycine max, diaheliotropism, irrigation, leaf area index, paraheliotropism. Respostas heliotrópicas de cultivares de soja em três estádios fenológicos e dois regimes hídricosResumo -Os objetivos deste trabalho foram determinar o movimento heliotrópico dos trifólios superiores de duas cultivares de soja, BR 16 e Embrapa 48, durante o dia, em três estádios fenológicos e em dois regimes hídricos e determinar o impacto da irrigação e do movimento foliar diário nas características agronômicas e na produção de grãos. Movimentos heliotrópicos foram determinados a cada hora, em três estádios fenológicos: V4-V6, V7-V10 e R5, em parcelas irrigadas e não irrigadas. Para cada estágio, a elevação do folíolo e o azimute foram medidos por hora. Em índices de área foliar (IAF) baixo e médio (V4-V6 e V7-V10), o diaheliotropismo foi levemente mais intenso e frequente nas plantas sem irrigação do que nas irrigadas, e somente nas primeiras horas matinais e últimas horas da tarde. Em R5 (alto IAF), o paraheliotropismo dos trifólios superiores foi predominante e mais intenso em plantas não irrigadas. Os movimentos heliotrópicos se correlacionaram com o ganho de carbono mas não com o ambiente (intensidade de luz ou temperatura), para medidas às 11 horas. 'Embrapa 48' apresenta maior paraheliotropismo do que 'BR 16', em plantas com alto IAF enquanto 'BR 16' apresenta menor plasticidade nas respostas heliotrópicas nas parcelas irrigadas. Apesar de diferenças no heliotropismo, o genótipo e disponibilidade de água não influenciaram a produção de grãos.Termos para indexação: Glycine max, cosseno, diaheliotropismo, irrigação, índice de área foliar, paraheliotropismo.

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Section: Introductionmentioning

confidence: 99%

Heliotropic responses of soybean cultivars at three phenological stages and under two water regimes

Rakocevic

Neumaier

Oliveira

et al. 2010

Pesq. agropec. bras.

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“…Heliotropism can be divided into two classes: (i) diaheliotropism, in which the leaf lamina become oriented at an angle perpendicular to incoming light; and (ii) paraheliotropism, where leaf lamina orient parallel to the light (Koller, 1986(Koller, , 1990Liu et al, 2007). Light interception is maximized by diaheliotropism and minimized by paraheliotropism (Koller 1986(Koller , 1990Bielenberg et al, 2003;Pastenes et al, 2005). However, under natural conditions, some solar-tracking plants can also move their leaves to avoid full exposure to sunlight, minimizing heating and water stress (Caldas et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Leaf heliotropism in Styrax camporum Pohl from the Brazilian cerrado: distinct gas exchange and leaf structure, but similar leaf temperature and water relations

Habermann

Machado

Guimarães

et al. 2008

Braz. J. Plant Physiol.

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Styrax camporum is a common shrub species from the cerrado regions of São Paulo State, Brazil. Although its leaves do not have a morphologically delimited pulvinus, the apical leaves are oriented parallel to the sun (paraheliotropic leaves), most notably around noon. Horizontal leaves at the base of shoots are oriented perpendicular to the sun's rays (diaheliotropic leaves). The ecophysiological significance of this is not fully understood. We investigated how paraheliotropism influences daily CO 2 assimilation (A) and other gas exchange rates, water relations, leaf temperature (T l ), and how these relate to leaf structure as assessed by anatomical leaf descriptions. Paraheliotropic leaves had greater A and stomatal conductance (g s ), which led to greater transpiration rates (E) during most of the day. However, no categorical data proved that these responses were responsible for the lower T l for vertical leaves, which only occurred at 1100 h and 1600 h. There was no indication that Tl influenced A, E, or g s . However, diaheliotropic leaves did not assimilate less carbon because of a smaller stomatal aperture. Both leaf types had satisfactory stomatal apertures and the same g s range, resulting in similar intercellular CO 2 levels. Paraheliotropic leaves had higher A rates under increased irradiance, suggesting an avoidance of excessive irradiance. Both leaf types had compact spongy parenchyma, representing an increased photosynthetic capacity per unit leaf area. Paraheliotropism in S. camporum does not seem to be related to leaf temperature control, even in the stressful Brazilian cerrado habitat. Key words: Brazilian savanna, ecophysiology, gas exchange, leaf movements, leaf temperature, photosynthesis, Styracaceae Heliotropismo foliar em Styrax camporum Pohl, uma espécie do cerrado brasileiro -padrões distintos de trocas gasosas e estrutura foliar, porém com temperatura foliar e relações hídricas similares: Styrax camporum é uma espécie arbustiva comum dos cerrados do Estado de São Paulo, Brasil. Embora suas folhas não tenham pulvino morfologicamente delimitado, as folhas apicais são orientadas paralelamente à incidência da radiação solar (folhas paraheliotrópicas), especialmente às 1200 h. Folhas horizontais estáticas das partes basais dos ramos são orientadas perpendicularmente aos raios solares (folhas diaheliotrópicas). O significado ecofisiológico do fenômeno não foi ainda completamente elucidado. Investigou-se como o paraheliotropismo influencia a assimilação diária de CO 2 (A) e outras taxas de trocas gasosas, relações hídricas, temperatura foliar (T f ) e suas relações com a estrutura da folha, avaliada por suas descrições anatômicas. Folhas paraheliotrópicas apresentaram maiores A e condutância estomática (g s ), o que levou à maior taxa de transpiração (E) durante grande parte do dia. Todavia, não houve dados categóricos assegurando que estas respostas tenham determinado menor T f para as folhas verticais, que ocorreu apenas às 1100 e 1600 h. Não houve nenhuma indicação de que T f influenciou A, ...

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“…On clear days paraheliotropism can reduce total radiant energy on the leaf blade by 20-30% . Therefore, these leaf movements have an influence on leaf energy balance, leaf temperature, transpirational water loss, carbon gain through photosynthesis, water use efficiency (WUE), photoinhibition, and the return in carbon of the nitrogen invested in photosynthesis (Koller et al, 1985;Ludlow and Bjorkman, 1987;Ehleringer, 1989 and1991;Berg and Heuchelin, 1990;Forseth, 1990;Bielenberg et al, 2003). The regulation of all these factors may give these plants an advantage in growth and seed production when compared to plants with stationary leaves.…”

Section: Introductionmentioning

confidence: 99%

Heliotropism and water availability effects on flowering dynamics and seed production in Macroptilium lathyroides

Santos

Rosa

Franke

et al. 2006

Rev. bras. sementes

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The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well-watered plants, with no statistically significant effect of leaf movements.

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Paraheliotropism in two Phaseolus species: combined effects of photon flux density and pulvinus temperature, and consequences for leaf gas exchange

Cited by 34 publications

References 30 publications

Heliotropic responses of soybean cultivars at three phenological stages and under two water regimes

Heliotropic responses of soybean cultivars at three phenological stages and under two water regimes

Leaf heliotropism in Styrax camporum Pohl from the Brazilian cerrado: distinct gas exchange and leaf structure, but similar leaf temperature and water relations

Heliotropism and water availability effects on flowering dynamics and seed production in Macroptilium lathyroides

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