Tree physiologyPub Date : 2025-03-08DOI: 10.1093/treephys/tpaf014
Yuehan Tian, Enzai Du, Yang Tang, Nan Xia
{"title":"Distinct seasonality of nutrients in twigs and leaves of temperate trees.","authors":"Yuehan Tian, Enzai Du, Yang Tang, Nan Xia","doi":"10.1093/treephys/tpaf014","DOIUrl":"10.1093/treephys/tpaf014","url":null,"abstract":"<p><p>Seasonal variation of nutrient concentrations in different organs is an essential strategy for temperate trees to maintain growth and function. The seasonal variations and variability (i.e., seasonality) of leaf nutrient concentrations have been well documented, while the trends and magnitudes of such seasonal variations in other tree organs (e.g., twigs) and their associations with leaf nutrients remain poorly understood. We measured the concentrations of 10 nutrients (nitrogen, N; phosphorus, P; potassium, K; calcium, Ca; magnesium, Mg; iron, Fe; manganese, Mn; copper, Cu; zinc, Zn; boron, B) in twigs and leaves of four temperate tree species (i.e., Pinus tabuliformis, Ginkgo biloba, Cotinus coggygria, and Sophora japonica) to explore their seasonal variations and seasonality. Our results showed that macronutrient concentrations (N, P, K, Ca, and Mg) were significantly higher in leaves and micronutrient concentrations (Fe, Mn, Cu, and Zn) were significantly higher in twigs. Concentrations of P and K both showed a negative seasonal covariation between twigs and leaves, while Ca, Fe, Mn, Cu, Zn, and B showed an opposite relationship. Compared with mobile nutrients, nonmobile nutrients exhibited significantly greater seasonality in the leaves but there were no such differences in twigs. The seasonality of nutrient concentrations in twigs was significantly stronger than in leaves and they were positively correlated. Additionally, nutrients with higher physiological requirements in leaves showed weaker seasonality, confirming the hypothesis of seasonal stability of high-demand nutrients, while such relationships were not statistically significant for twigs. This study demonstrates distinct seasonality of nutrients in twigs and leaves of temperate woody plants. These findings highlight that high-demand nutrients show stronger seasonal stability in leaves but not in twigs and uncover the seasonal coordination between twigs and leaves as a nutrient conservation strategy.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143068215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-08DOI: 10.1093/treephys/tpaf018
Yating Li, Guenter Hoch
{"title":"Physiological adjustments of temperate tree species and herbs in response to low root temperatures.","authors":"Yating Li, Guenter Hoch","doi":"10.1093/treephys/tpaf018","DOIUrl":"10.1093/treephys/tpaf018","url":null,"abstract":"<p><p>Hydraulic constraints induced by low root temperature might be a major cause for the low temperature limit of plants. However, to date most of our knowledge on the physiological effects of low root temperatures is derived from short-term lab experiments, with very limited information on potential adjustments to continuous low temperature stress. In this study, we quantified the cold sensitivity of root water uptake and transport to leaves in seedlings of different functional plant types (conifers, broadleaved trees and annual herbs) by 2H-H2O labeling after exposure to three constant root temperatures (15 °C, 7 °C and 2 °C) but the same higher aboveground temperatures (between 20 and 25 °C). We investigated changes in the cold sensitivity of roots after 0, 10 and 20 days prolonged exposure to the respective root temperatures. Plant water uptake and transport was decreased by lowered root temperature in all species, with a stronger effect at 2 °C compared with 7 °C. The water uptake and transport capacity of tree species gradually declined over the 20-day treatment, while the two investigated herbs exhibited immediately strong decreases that were kept at the same low level throughout the entire experiment time. The speed of the water uptake reduction across the 20 days observation period differed among the tree species and was faster in species that reach their natural upper distribution limits at lower elevations compared with species that occur at subalpine regions. The restricted root water uptake and transport was accompanied by reductions in leaf water potential, stomatal conductance and growth. Overall, our study showed increasingly reduced capacity for water uptake and transport across functional plant groups at continuous cold root conditions. This result might indicate accumulative negative effects on cell membrane permeability for water in roots, or a controlled reduction of root water conductivity of temperate trees in preparation for winter dormancy.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":"45 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143664604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-08DOI: 10.1093/treephys/tpaf020
Yi-Xue Zhang, Pei-Li Fu, Qiao-Shun Yan, Achim Bräuning, Ze-Xin Fan
{"title":"Intra-annual stem radius growth and cell formation of two diffuse-porous tree species in a subtropical forest in Southwest China.","authors":"Yi-Xue Zhang, Pei-Li Fu, Qiao-Shun Yan, Achim Bräuning, Ze-Xin Fan","doi":"10.1093/treephys/tpaf020","DOIUrl":"10.1093/treephys/tpaf020","url":null,"abstract":"<p><p>Studying tree growth and xylem formation is essential for understanding tree resilience to extreme droughts, which are expected to intensify with climate warming. However, researches on intra-annual stem growth and xylogenesis remain limited, particularly in moist subtropical forests. This study monitored the intra-annual stem radius growth and xylem formation of two diffuse-porous tree species, Stewartia pteropetiolata W. C. Cheng and Schima noronhae Reinw. ex Blume, in a subtropical evergreen broadleaved forest in Southwest China, using high-resolution dendrometer measurements for recording stem growth and micro-coring for xylem formation. We analyzed the seasonal patterns of stem radius growth and xylem formation and their responses to seasonal climate variability. Our results revealed that S. noronhae, found at lower elevations, exhibited a later onset of stem growth and xylogenesis, developing wider vessels with thinner walls during a longer enlarging phase. In contrast, S. pteropetiolata, which is distributed at higher elevations, produced smaller vessels with thicker walls during a longer cell-wall thickening phase. Both species showed high relative growth rates under conditions of high temperatures and low vapor pressure deficit. More specifically, S. noronhae maintained higher relative growth rates under a narrower range of favorable temperature and soil water conditions during the rainy season, while S. pteropetiolata sustained growth for a longer growth period in colder and drier conditions. These findings enhance the understanding of angiosperm wood cell kinetics and the eco-physiological response of diffuse-porous trees to climate change in moist subtropical forests.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11937825/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143442092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-08DOI: 10.1093/treephys/tpaf011
Feng Que, Yaqi Zhu, Qingnan Liu, Qiang Wei
{"title":"Strigolactones regulate Bambusa multiplex sheath senescence by promoting chlorophyll degradation.","authors":"Feng Que, Yaqi Zhu, Qingnan Liu, Qiang Wei","doi":"10.1093/treephys/tpaf011","DOIUrl":"10.1093/treephys/tpaf011","url":null,"abstract":"<p><p>Culm sheaths are capable of photosynthesis and are an important class of non-leaf organs in bamboo plants. The source-sink interaction mechanism has been found to play an important role in the interaction between culm sheaths and internodes in Bambusa multiplex. Research on the regulatory mechanisms of culm sheath senescence is important for the study of internode growth, but reports in this regard are limited. In this study, a weighted gene co-expression network analysis was performed on transcriptome data of B. multiplex culm sheaths at different developmental stages and identified some gene modules significantly related to the typical senescence stages (SS3 and SS4). Among these modules, one module significantly associated with both SS3 and SS4 was identified, and its hub gene (BmCCD8) was a key gene of the strigolactones (SLs) synthesis pathway. To verify the relationship between SLs and culm sheath senescence, we performed experiments such as detection of endogenous hormone, treatment with exogenous hormones, transmission electron microscopic observation and detection of gene expression levels. A positive relationship was found between the SL content and the degree of sheath senescence. Treatment with the artificial SL analog GR24 resulted in a significant decrease in chlorophyll content in the sheath, while treatment with the SL synthesis inhibitor Tis108 led to a significant increase in chlorophyll content. A different response pattern to exogenous GR24 and Tis108 was also observed in genes related to the chlorophyll degradation pathway. Chloroplasts were also found to begin degradation one day after the end of exogenous GR24 treatment. Thus, we concluded that SLs may regulate culm sheath senescence by promoting chlorophyll degradation.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-08DOI: 10.1093/treephys/tpaf018
Yating Li, Guenter Hoch
{"title":"Physiological adjustments of temperate tree species and herbs in response to low root temperatures.","authors":"Yating Li, Guenter Hoch","doi":"10.1093/treephys/tpaf018","DOIUrl":"10.1093/treephys/tpaf018","url":null,"abstract":"<p><p>Hydraulic constraints induced by low root temperature might be a major cause for the low temperature limit of plants. However, to date most of our knowledge on the physiological effects of low root temperatures is derived from short-term lab experiments, with very limited information on potential adjustments to continuous low temperature stress. In this study, we quantified the cold sensitivity of root water uptake and transport to leaves in seedlings of different functional plant types (conifers, broadleaved trees and annual herbs) by 2H-H2O labeling after exposure to three constant root temperatures (15 °C, 7 °C and 2 °C) but the same higher aboveground temperatures (between 20 and 25 °C). We investigated changes in the cold sensitivity of roots after 0, 10 and 20 days prolonged exposure to the respective root temperatures. Plant water uptake and transport was decreased by lowered root temperature in all species, with a stronger effect at 2 °C compared with 7 °C. The water uptake and transport capacity of tree species gradually declined over the 20-day treatment, while the two investigated herbs exhibited immediately strong decreases that were kept at the same low level throughout the entire experiment time. The speed of the water uptake reduction across the 20 days observation period differed among the tree species and was faster in species that reach their natural upper distribution limits at lower elevations compared with species that occur at subalpine regions. The restricted root water uptake and transport was accompanied by reductions in leaf water potential, stomatal conductance and growth. Overall, our study showed increasingly reduced capacity for water uptake and transport across functional plant groups at continuous cold root conditions. This result might indicate accumulative negative effects on cell membrane permeability for water in roots, or a controlled reduction of root water conductivity of temperate trees in preparation for winter dormancy.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11922318/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143190609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-03DOI: 10.1093/treephys/tpaf009
Dor Haim, Madhuri Pochamreddy, Adi Doron-Faigenboim, Itzahk Kamara, Giora Ben-Ari, Avi Sadka
{"title":"Auxin treatment reduces inflorescences number and delays bud development in the alternate bearing Citrus cultivar Murcott mandarin.","authors":"Dor Haim, Madhuri Pochamreddy, Adi Doron-Faigenboim, Itzahk Kamara, Giora Ben-Ari, Avi Sadka","doi":"10.1093/treephys/tpaf009","DOIUrl":"10.1093/treephys/tpaf009","url":null,"abstract":"<p><p>Specific cultivars of many commercial fruit trees undergo cycles of heavy fruit load (ON-crop) one year, followed by low fruit load (OFF-crop) the next (termed alternate bearing). Fruit load may affect flowering at various developmental stages, and its presence is suggested to generate a flowering-inhibitory signal. In a previous report, we showed that the presence of fruit induces polar auxin transport from the fruit into the stem, interfering with indole acetic acid release from the bud and thus elevating its levels in the bud meristem. To better understand the relationship between auxin homeostasis in the bud and flowering, indole acetic acid or 2,4-dichlorophenoxyacetic acid (2,4-D) was applied with the polar auxin transport blocker 2,3,5-triiodobenzoic acid to OFF-crop 'Murcott' mandarin (Citrus reticulata × Citrus sinensis) trees during the flowering-induction period. The treatment reduced inflorescence number and delayed bud development. Transcriptome analysis following the treatment revealed a reduction in the expression of a few flowering-control genes, including LEAFY and SQUAMOSA PROMOTER BINDING PROTEIN-LIKE. In addition, genes related to carbohydrate metabolism were reduced. We suggest that the elevation of auxin levels in the bud by heavy fruit load directly affects the expression of flowering-control, flower-development and developmental genes.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":"45 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143664638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-03DOI: 10.1093/treephys/tpaf009
Dor Haim, Madhuri Pochamreddy, Adi Doron-Faigenboim, Itzahk Kamara, Giora Ben-Ari, Avi Sadka
{"title":"Auxin treatment reduces inflorescences number and delays bud development in the alternate bearing Citrus cultivar Murcott mandarin.","authors":"Dor Haim, Madhuri Pochamreddy, Adi Doron-Faigenboim, Itzahk Kamara, Giora Ben-Ari, Avi Sadka","doi":"10.1093/treephys/tpaf009","DOIUrl":"10.1093/treephys/tpaf009","url":null,"abstract":"<p><p>Specific cultivars of many commercial fruit trees undergo cycles of heavy fruit load (ON-crop) one year, followed by low fruit load (OFF-crop) the next (termed alternate bearing). Fruit load may affect flowering at various developmental stages, and its presence is suggested to generate a flowering-inhibitory signal. In a previous report, we showed that the presence of fruit induces polar auxin transport from the fruit into the stem, interfering with indole acetic acid release from the bud and thus elevating its levels in the bud meristem. To better understand the relationship between auxin homeostasis in the bud and flowering, indole acetic acid or 2,4-dichlorophenoxyacetic acid (2,4-D) was applied with the polar auxin transport blocker 2,3,5-triiodobenzoic acid to OFF-crop 'Murcott' mandarin (Citrus reticulata × Citrus sinensis) trees during the flowering-induction period. The treatment reduced inflorescence number and delayed bud development. Transcriptome analysis following the treatment revealed a reduction in the expression of a few flowering-control genes, including LEAFY and SQUAMOSA PROMOTER BINDING PROTEIN-LIKE. In addition, genes related to carbohydrate metabolism were reduced. We suggest that the elevation of auxin levels in the bud by heavy fruit load directly affects the expression of flowering-control, flower-development and developmental genes.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-03DOI: 10.1093/treephys/tpae153
Emmelia J Braun, Charles D Southwick, Maquelle N Garcia, Tyeen C Taylor, Kelvin Acebron, João Victor F C Rodrigues, Marciel J Ferreira, Raimundo C de Oliveira, Loren P Albert
{"title":"Prospects for high-throughput estimates of photosynthetic parameters in tropical trees using the Dynamic Assimilation™ Technique.","authors":"Emmelia J Braun, Charles D Southwick, Maquelle N Garcia, Tyeen C Taylor, Kelvin Acebron, João Victor F C Rodrigues, Marciel J Ferreira, Raimundo C de Oliveira, Loren P Albert","doi":"10.1093/treephys/tpae153","DOIUrl":"10.1093/treephys/tpae153","url":null,"abstract":"<p><p>Amazônia is a species-rich region of immense importance to Earth's water and carbon cycling. Photosynthesis drives the global carbon cycle, so understanding photosynthetic differences across diverse landscapes is a key task of ecophysiology and ecosystem science. Unfortunately, due to physiological and logistical constraints, ground-based photosynthesis data in Amazônia remain scarce and the 'traditional' steady-state (SS) method of gas exchange is slow and inefficient. The Dynamic Assimilation™ Technique (DAT) promises a new way to perform A/Ci curves rapidly without requiring SS conditions. Thus far, this technique has only been validated in greenhouse or agricultural-field-grown species and has yet to be tested in forest trees of diverse physiology morphology and environmental adaptation. To test the utility of the DAT in a complex tropical forest ecosystem, we compared the DAT with the SS method in 13 Amazonian trees in situ. We found strong agreement between Vcmax from DAT curves and SS curves, while Jmax was underestimated in DAT curves. We conclude that the DAT provides a robust and rapid estimation of Vcmax. We also identified diverse and unexpected DAT curve shapes among some trees, including the presence of an 'overshoot' in assimilation beyond model-derived ribulose-1,5-bisphosphate (RuBP) regeneration limitations. The presence of overshoot may elucidate microclimate and species differences in RuBP regeneration rates and emphasizes the considerable importance of DAT curve protocol specifications, such as the effect of ramp rate and direction on Jmax and TPU. Overall, the DAT saved time relative to the SS method and proved to be an effective and rapid method for quantifying Vcmax in tropical trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":"45 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143664611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-03DOI: 10.1093/treephys/tpaf016
Álvaro Camisón, Pedro Monteiro, F Javier Dorado, Paloma Sánchez-Bel, Frederico Leitão, Mónica Meijón, Gloria Pinto
{"title":"Choosing the right signaling pathway: hormone responses to Phytophthora cinnamomi during compatible and incompatible interactions with chestnut (Castanea spp.).","authors":"Álvaro Camisón, Pedro Monteiro, F Javier Dorado, Paloma Sánchez-Bel, Frederico Leitão, Mónica Meijón, Gloria Pinto","doi":"10.1093/treephys/tpaf016","DOIUrl":"10.1093/treephys/tpaf016","url":null,"abstract":"<p><p>Ink disease caused by the hemibiotrophic root pathogen Phytophthora cinnamomi (Pc) is devastating for the European chestnut (Castanea sativa), unlike Asian chestnuts and interspecific hybrids, which are resistant to Pc. The role that hormone responses play for Pc resistance remains little understood, especially regarding the temporal regulation of hormone responses. We explored the relationship between changes in tree health and physiology and alterations in leaf and root phytohormones and primary and secondary metabolites during compatible and incompatible Castanea spp.-Pc interactions. Susceptible (S) C. sativa and resistant (R) C. sativa × C. crenata ramets were inoculated with Pc in roots and assessed for disease progression, leaf physiology and biochemistry at 1, 3, 5 and 8 days after inoculation (d.a.i.). In S chestnuts, Pc increasingly deteriorated the leaf physiological functioning by decreasing leaf CO2 assimilation, stomatal conductance, transpiration rate, chlorophylls content and the maximum quantum yield of the photosystem II over time, triggering aerial symptoms (leaf wilting and chlorosis) 8 d.a.i. Pc had little impact on the leaf physiological functioning of R chestnuts, which remained asymptomatic. In roots of S chestnuts, Pc transiently induced jasmonates signaling (5 d.a.i.) while impairing root carbohydrates metabolism over time. In leaves, a transient antioxidant burst (5 d.a.i.) followed by abscisic acid (ABA) accumulation (8 d.a.i.) was observed. R chestnuts responded to Pc by up-regulating root salicylic acid (SA) at early (1 d.a.i.) and late (8 d.a.i.) infection stages, in an antagonistic crosstalk with root ABA. Overall, the results pinpoint an important role of SA in mediating the resistant response of chestnuts to Pc, but also show that the specific hormone pathways induced by Pc are genotype dependent. The study also highlights that the dynamic nature of hormone responses over time must be considered when elucidating hormone-regulated responses to Pc.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":"45 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143664646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tree physiologyPub Date : 2025-03-03DOI: 10.1093/treephys/tpae153
Emmelia J Braun, Charles D Southwick, Maquelle N Garcia, Tyeen C Taylor, Kelvin Acebron, João Victor F C Rodrigues, Marciel J Ferreira, Raimundo C de Oliveira, Loren P Albert
{"title":"Prospects for high-throughput estimates of photosynthetic parameters in tropical trees using the Dynamic Assimilation™ Technique.","authors":"Emmelia J Braun, Charles D Southwick, Maquelle N Garcia, Tyeen C Taylor, Kelvin Acebron, João Victor F C Rodrigues, Marciel J Ferreira, Raimundo C de Oliveira, Loren P Albert","doi":"10.1093/treephys/tpae153","DOIUrl":"10.1093/treephys/tpae153","url":null,"abstract":"<p><p>Amazônia is a species-rich region of immense importance to Earth's water and carbon cycling. Photosynthesis drives the global carbon cycle, so understanding photosynthetic differences across diverse landscapes is a key task of ecophysiology and ecosystem science. Unfortunately, due to physiological and logistical constraints, ground-based photosynthesis data in Amazônia remain scarce and the 'traditional' steady-state (SS) method of gas exchange is slow and inefficient. The Dynamic Assimilation™ Technique (DAT) promises a new way to perform A/Ci curves rapidly without requiring SS conditions. Thus far, this technique has only been validated in greenhouse or agricultural-field-grown species and has yet to be tested in forest trees of diverse physiology morphology and environmental adaptation. To test the utility of the DAT in a complex tropical forest ecosystem, we compared the DAT with the SS method in 13 Amazonian trees in situ. We found strong agreement between Vcmax from DAT curves and SS curves, while Jmax was underestimated in DAT curves. We conclude that the DAT provides a robust and rapid estimation of Vcmax. We also identified diverse and unexpected DAT curve shapes among some trees, including the presence of an 'overshoot' in assimilation beyond model-derived ribulose-1,5-bisphosphate (RuBP) regeneration limitations. The presence of overshoot may elucidate microclimate and species differences in RuBP regeneration rates and emphasizes the considerable importance of DAT curve protocol specifications, such as the effect of ramp rate and direction on Jmax and TPU. Overall, the DAT saved time relative to the SS method and proved to be an effective and rapid method for quantifying Vcmax in tropical trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142839584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}