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Kongjarat W, Han L, Aritsara ANA, Zhang SB, Zhao GJ, Zhang YJ, Maenpuen P, Li YM, Zou YK, Li MY, Li XN, Tao LB, Chen YJ. Hydraulic properties and drought response of a tropical bamboo ( Cephalostachyum pergracile). PLANT DIVERSITY 2024; 46:406-415. [PMID: 38798721 PMCID: PMC11119542 DOI: 10.1016/j.pld.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 05/29/2024]
Abstract
Bamboo plants are an essential component of tropical ecosystems, yet their vulnerability to climate extremes, such as drought, is poorly understood due to limited knowledge of their hydraulic properties. Cephalostachyum pergracile, a commonly used tropical bamboo species, exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019, but the underlying mechanisms remain unclear. This study investigated the leaf and stem hydraulic traits related to drought responses, including leaf-stem embolism resistance (P50leaf; P50stem) estimated using optical and X-ray microtomography methods, leaf pressure-volume and water-releasing curves. Additionally, we investigated the seasonal water potentials, native embolism level (PLC) and xylem water source using stable isotope. We found that C. pergracile exhibited strong resistance to embolism, showing low P50leaf, P50stem, and turgor loss point, despite its rapid leaf water loss. Interestingly, its leaves displayed greater resistance to embolism than its stem, suggesting a lack of effective hydraulic vulnerability segmentation (HVS) to protect the stem from excessive xylem tension. During the dry season, approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer. Consequently, significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87 ± 2.33% in the wet season to 12.87 ± 4.09% in the dry season were observed. In summary, this study demonstrated that the rapid leaf water loss, high reliance on surface water, and a lack of effective HVS in C. pergracile accelerated water depletion and increased xylem embolism even in the typical dry season, which may explain its high mortality rate during extreme drought events in 2019.
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Affiliation(s)
- Wanwalee Kongjarat
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Lu Han
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Amy Ny Aina Aritsara
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Gao-Juan Zhao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, USA
- Climate Change Institute, University of Maine, Orono, ME 04469, USA
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Mei Li
- School of Biological and Chemical Science, Pu’er University, Xueyuan Road, Yunnan 665000, China
| | - Yi-Ke Zou
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Ming-Yi Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Xue-Nan Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- School of Ecology and Environment, Southwest Forestry University, Kunming, Yunnan 650224, China
| | - Lian-Bin Tao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- T-STAR Core Team, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan 666303, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan 653300, China
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Tang W, Liu X, Liang X, Liu H, Yu K, He P, McAdam S, Zhao H, Ye Q. Hydraulic vulnerability difference between branches and roots increases with environmental aridity. Oecologia 2024; 205:177-190. [PMID: 38772916 DOI: 10.1007/s00442-024-05562-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 05/01/2024] [Indexed: 05/23/2024]
Abstract
The vulnerability of plant xylem to embolism can be described as the water potential at which xylem conductivity is lost by 50% (P50). According to the traditional hypothesis of hydraulic vulnerability segmentation, the difference in vulnerability to embolism between branches and roots is positive (P50 root-branch > 0). It is not clear whether this occurs broadly across species or how segmentation might vary across aridity gradients. We compiled hydraulic and anatomical datasets from branches and roots across 104 woody species (including new measurements from 10 species) in four biomes to investigate the relationships between P50 root-branch and environmental factors associated with aridity. We found a positive P50 root-branch relationship across species, and evidence that P50 root-branch increases with aridity. Branch xylem hydraulic conductivity transitioned from more efficient (e.g., wider conduit, higher hydraulic conductivity) to safer (e.g., narrower conduit, more negative P50) in response to the increase of aridity, while root xylem hydraulic conductivity remained unchanged across aridity gradients. Our results demonstrate that the hydraulic vulnerability difference between branches and roots is more positive in species from arid regions, largely driven by modifications to branch traits.
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Affiliation(s)
- Weize Tang
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaorong Liu
- Sichuan University of Arts and Science, Tashi Road 519, Dazhou, 635000, China
| | - Xingyun Liang
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China
| | - Hui Liu
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China
| | - Kailiang Yu
- High Meadows Environmental Institute, Princeton University, Princeton, NJ, USA
| | - Pengcheng He
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China
| | - Scott McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Han Zhao
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China
| | - Qing Ye
- Guangdong Provincial Key Laboratory of Applied Botany and Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, No. 723, Xingke Road, Tianhe District, Guangzhou, 510650, China.
- College of Life Sciences, Gannan Normal University, Ganzhou, 341000, China.
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Qie YD, Zhang QW, McAdam SA, Cao KF. Stomatal dynamics are regulated by leaf hydraulic traits and guard cell anatomy in nine true mangrove species. PLANT DIVERSITY 2024; 46:395-405. [PMID: 38798723 PMCID: PMC11119510 DOI: 10.1016/j.pld.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/04/2024] [Accepted: 02/05/2024] [Indexed: 05/29/2024]
Abstract
Stomatal regulation is critical for mangroves to survive in the hyper-saline intertidal zone where water stress is severe and water availability is highly fluctuant. However, very little is known about the stomatal sensitivity to vapour pressure deficit (VPD) in mangroves, and its co-ordination with stomatal morphology and leaf hydraulic traits. We measured the stomatal response to a step increase in VPD in situ, stomatal anatomy, leaf hydraulic vulnerability and pressure-volume traits in nine true mangrove species of five families and collected the data of genome size. We aimed to answer two questions: (1) Does stomatal morphology influence stomatal dynamics in response to a high VPD in mangroves? with a consideration of possible influence of genome size on stomatal morphology; and (2) do leaf hydraulic traits influence stomatal sensitivity to VPD in mangroves? We found that the stomata of mangrove plants were highly sensitive to a step rise in VPD and the stomatal responses were directly affected by stomatal anatomy and hydraulic traits. Smaller, denser stomata was correlated with faster stomatal closure at high VPD across the species of Rhizophoraceae, and stomata size negatively and vein density positively correlated with genome size. Less negative leaf osmotic pressure at the full turgor (πo) was related to higher operating steady-state stomatal conductance (gs); and a higher leaf capacitance (Cleaf) and more embolism resistant leaf xylem were associated with slower stomatal responses to an increase in VPD. In addition, stomatal responsiveness to VPD was indirectly affected by leaf morphological traits, which were affected by site salinity and consequently leaf water status. Our results demonstrate that mangroves display a unique relationship between genome size, stomatal size and vein packing, and that stomatal responsiveness to VPD is regulated by leaf hydraulic traits and stomatal morphology. Our work provides a quantitative framework to better understand of stomatal regulation in mangroves in an environment with high salinity and dynamic water availability.
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Affiliation(s)
- Ya-Dong Qie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China
| | - Qi-Wei Zhang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University, Guilin 541001, China
- Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin, Guangxi Normal University, Guilin 541001, China
| | - Scott A.M. McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Kun-Fang Cao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China
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Zhang Y, Cao JJ, Yang QP, Wu MZ, Zhao Y, Kong DL. The worldwide allometric relationship in anatomical structures for plant roots. PLANT DIVERSITY 2023; 45:621-629. [PMID: 38197011 PMCID: PMC10772186 DOI: 10.1016/j.pld.2023.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 04/15/2023] [Accepted: 05/25/2023] [Indexed: 01/11/2024]
Abstract
The cortex (i.e., absorptive tissue) and stele (transportive vascular tissue) are fundamental to the function of plant roots. Unraveling how these anatomical structures are assembled in absorptive roots is essential for our understanding of plant ecology, physiology, and plant responses to global environmental changes. In this review, we first compile a large data set on anatomical traits in absorptive roots, including cortex thickness and stele radius, across 698 observations and 512 species. Using this data set, we reveal a common root allometry in absorptive root structures, i.e., cortex thickness increases much faster than stele radius with increasing root diameter (hereafter, root allometry). Root allometry is further validated within and across plant growth forms (woody, grass, and liana species), mycorrhiza types (arbuscular mycorrhiza, ectomycorrhiza, and orchid mycorrhizas), phylogenetic gradients (from ferns to Orchidaceae), and environmental change scenarios (e.g., elevation of atmospheric CO2 concentration and nitrogen fertilization). These findings indicate that root allometry is common in plants. Importantly, root allometry varies greatly across species. We then summarize recent research on the mechanisms of root allometry and potential issues regarding these mechanisms. We further discuss ecological and evolutionary implications of root allometry. Finally, we propose several important research directions that should be pursued regarding root allometry.
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Affiliation(s)
- Yue Zhang
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Jing-Jing Cao
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Qing-Pei Yang
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Ming-Zuo Wu
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Yong Zhao
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - De-Liang Kong
- College of Forestry, Henan Agricultural University, Zhengzhou 450002, China
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