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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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Guo L, Liu Y, Liu L, Yin P, Liu C, Li J. Study of the mechanism of embolism removal in xylem vessels by using microfluidic devices. LAB ON A CHIP 2023; 23:737-747. [PMID: 36594973 DOI: 10.1039/d2lc00945e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Determining the mechanism that effects embolism repair in the xylem vessels of plants is of great significance in predicting plant distribution and the screening of drought-resistant plants. However, the mechanism of perforation plates of xylem vessels in the acceleration of embolism repair is still not clear by using conventional methods of anatomy and visualization technology. Microfluidic devices have shown their ability to simulate physiological environments and conduct quantitative experiments. This work proposes a biomimetic microfluidic device to study the mechanism of perforation plates of xylem vessels in the acceleration of embolism repair. The results proffered that the perforation plates increase the rate of embolism removal by increasing the pressure differential through the vessel, and the rate of embolism removal is related to the structural parameters of the perforation plate. A combination of the perforation size, the vessel diameter and the perforation plate angle can be optimised to generate higher pressure differentials, which can accelerate the process of embolism repair. This work provides a new method for studying the mechanism of microstructures of natural plants. Furthermore, the mechanism that perforation plates accelerate embolism repair was applied to an electrochemical flow sensor for online determination of heavy metal ions. Test results of this application indicate that the mechanism can be applied in the engineering field to solve the problems of reduced sensitivity of devices, inaccuracy of analysis results and poor reaction performance caused by bubbles that are generated or introduced easily in microdevices, which paves the way for applying the theory to engineering.
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Affiliation(s)
- Lihua Guo
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Yuanchang Liu
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Li Liu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Penghe Yin
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Chong Liu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
| | - Jingmin Li
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, China.
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Sinsirimongkol K, Buasong A, Teppabut Y, Pholmanee N, Chen Y, Miller AJ, Punyasuk N. EgNRT2.3 and EgNAR2 expression are controlled by nitrogen deprivation and encode proteins that function as a two-component nitrate uptake system in oil palm. JOURNAL OF PLANT PHYSIOLOGY 2022; 279:153833. [PMID: 36257088 DOI: 10.1016/j.jplph.2022.153833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 09/29/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Oil palm (Elaeis guineensis Jacq.) is an important crop for oil and biodiesel production. Oil palm plantations require extensive fertilizer additions to achieve a high yield. Fertilizer application decisions and management for oil palm farming rely on leaf tissue and soil nutrient analyses with little information available to describe the key players for nutrient uptake. A molecular understanding of how nutrients, especially nitrogen (N), are taken up in oil palm is very important to improve fertilizer use and formulation practice in oil palm plantations. In this work, two nitrate uptake genes in oil palm, EgNRT2.3 and EgNAR2, were cloned and characterized. Spatial expression analysis showed high expression of these two genes was mainly found in un-lignified young roots. Interestingly, EgNRT2.3 and EgNAR2 were up-regulated by N deprivation, but their expression pattern depended on the form of N source. Promoter analysis of these two genes confirmed the presence of regulatory elements that support these expression patterns. The Xenopus oocyte assay showed that EgNRT2.3 and EgNAR2 had to act together to take up nitrate. The results suggest that EgNRT2.3 and EgNAR2 act as a two-component nitrate uptake system in oil palm.
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Affiliation(s)
| | - Atcharaporn Buasong
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Yada Teppabut
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Nutthida Pholmanee
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Yi Chen
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Anthony J Miller
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Napassorn Punyasuk
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
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Chen Z, Li S, Wan X, Liu S. Strategies of tree species to adapt to drought from leaf stomatal regulation and stem embolism resistance to root properties. FRONTIERS IN PLANT SCIENCE 2022; 13:926535. [PMID: 36237513 PMCID: PMC9552884 DOI: 10.3389/fpls.2022.926535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Considerable evidences highlight the occurrence of increasing widespread tree mortality as a result of global climate change-associated droughts. However, knowledge about the mechanisms underlying divergent strategies of various tree species to adapt to drought has remained remarkably insufficient. Leaf stomatal regulation and embolism resistance of stem xylem serves as two important strategies for tree species to prevent hydraulic failure and carbon starvation, as comprising interconnected physiological mechanisms underlying drought-induced tree mortality. Hence, the physiological and anatomical determinants of leaf stomatal regulation and stems xylem embolism resistance are evaluated and discussed. In addition, root properties related to drought tolerance are also reviewed. Species with greater investment in leaves and stems tend to maintain stomatal opening and resist stem embolism under drought conditions. The coordination between stomatal regulation and stem embolism resistance are summarized and discussed. Previous studies showed that hydraulic safety margin (HSM, the difference between minimum water potential and that causing xylem dysfunction) is a significant predictor of tree species mortality under drought conditions. Compared with HSM, stomatal safety margin (the difference between water potential at stomatal closure and that causing xylem dysfunction) more directly merge stomatal regulation strategies with xylem hydraulic strategies, illustrating a comprehensive framework to characterize plant response to drought. A combination of plant traits reflecting species' response and adaptation to drought should be established in the future, and we propose four specific urgent issues as future research priorities.
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Affiliation(s)
- Zhicheng Chen
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
| | - Shan Li
- Department of Environmental Science and Ecology, School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi’an, China
| | - Xianchong Wan
- Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China
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Wang L, Dai Y, Zhang J, Meng P, Wan X. Xylem structure and hydraulic characteristics of deep roots, shallow roots and branches of walnut under seasonal drought. BMC PLANT BIOLOGY 2022; 22:440. [PMID: 36104814 PMCID: PMC9472371 DOI: 10.1186/s12870-022-03815-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Despite the importance of root hydraulics, there is little research on the in situ dynamic responses of embolism formation and embolism repair of roots distributed in different soil depths in response to different water regimes. RESULTS The vessel diameter, hydraulic conductivity, and vulnerability to cavitation were in the order of deep root > shallow root > branch. The midday PLC of shallow root was the highest in the dry season, while the midday PLC of deep root slightly higher than that of branch with no significant difference in the two seasons. The capacity of embolism repair of roots was significantly greater than that of branch both in dry season and wet season. The xylem pressure was in the order of deep roots > shallow root > branch, and it was negative in most of the time for the latter two in the dry season, but positive for both of the roots during the observation period in the wet season. The NSC and starch content in roots were significantly higher than those in branches, especially in the dry season. In contrast, roots had lower content of soluble sugar. CONCLUSIONS The relatively stable water condition in soil, especially in the deep layers, is favorable for the development of larger-diameter vessels in root xylem, however it cannot prevent the root from forming embolism. The mechanism of embolism repair may be different in different parts of plants. Deep roots mainly depend on root pressure to refill the embolized vessels, while branches mainly depend on starch hydrolysis to soluble sugars to do the work, with shallow roots shifted between the two mechanisms in different moisture regimes. There is theoretically an obvious trade-off between conducting efficiency and safety over deep roots, shallow roots and branches. But in natural conditions, roots do not necessarily suffer more severe embolism than branches, maybe due to their root pressure-driven embolism repair and relatively good water conditions.
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Affiliation(s)
- Lin Wang
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Yongxin Dai
- College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, 030801, People's Republic of China
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Jinsong Zhang
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Ping Meng
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China
| | - Xianchong Wan
- Institute of New Forestry Technology, Chinese Academy of Forestry, Beijing, 100091, People's Republic of China.
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Hourly Relationship between Reference Evapotranspiration and Shoot Shrinkage in Walnut Trees and Pomegranate under Deficit Irrigation. PLANTS 2021; 11:plants11010031. [PMID: 35009035 PMCID: PMC8747659 DOI: 10.3390/plants11010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/16/2022]
Abstract
Diameter fluctuations of branches, shoots, or fruits are related to plant transpiration and water potential. In the past, several models have related dendrometric variables and evapotranspiration on a daily scale. However, trunk–branch shrinkage occurs only between dawn and midday, while evapotranspiration occurs most of the day from sunrise to sunset. Previous models have failed to incorporate this key fact. The objective of the present study was to assess the relationship of hourly daily shrinkage (HDS) between dawn and the next 4 h to the hourly reference evapotranspiration (EToh) of the same period in walnut trees and pomegranate plants under different irrigation regimes. Our data show that the relationship between EToh and HDS is much better than several previous models that included maximum daily shrinkage (MDS) and reference evapotranspiration (ETo). The novel slope analysis of the relationship between HDS versus time used here corresponds to the velocity at which the HDS occurs, which depends on the ETo intensity at that moment. This new method of analyzing this type of data calls for a revision of these models and sets a new baseline for future analysis.
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Bourbia I, Pritzkow C, Brodribb TJ. Herb and conifer roots show similar high sensitivity to water deficit. PLANT PHYSIOLOGY 2021; 186:1908-1918. [PMID: 34618104 PMCID: PMC8331161 DOI: 10.1093/plphys/kiab207] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 04/24/2021] [Indexed: 05/11/2023]
Abstract
Root systems play a major role in supplying the canopy with water, enabling photosynthesis and growth. Yet, much of the dynamic response of root hydraulics and its influence on gas exchange during soil drying and recovery remains uncertain. We examined the decline and recovery of the whole root hydraulic conductance (Kr) and canopy diffusive conductance (gc) during exposure to moderate water stress in two species with contrasting root systems: Tanacetum cinerariifolium (herbaceous Asteraceae) and Callitris rhomboidea (woody conifer). Optical dendrometers were used to record stem water potential at high temporal resolution and enabled non-invasive measurements of Kr calculated from the rapid relaxation kinetics of water potential in hydrating roots. We observed parallel declines in Kr and gc to <20% of unstressed levels during the early stages of water stress in both species. The recovery of Kr after rewatering differed between species. T. cinerariifolium recovered quickly, with 60% of Kr recovered within 2 h, while C. rhomboidea was much slower to return to its original Kr. Recovery of gc followed a similar trend to Kr in both species, with C. rhomboidea slower to recover. Our findings suggest that the pronounced sensitivity of Kr to drought is a common feature among different plant species, but recovery may vary depending on root type and water stress severity. Kr dynamics are proposed to modulate gc response during and following drought.
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Affiliation(s)
- Ibrahim Bourbia
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Carola Pritzkow
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Timothy J Brodribb
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
- Author for communication:
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Reingwirtz I, Uretsky J, Cuneo IF, Knipfer T, Reyes C, Walker MA, McElrone AJ. Inherent and Stress-Induced Responses of Fine Root Morphology and Anatomy in Commercial Grapevine Rootstocks with Contrasting Drought Resistance. PLANTS (BASEL, SWITZERLAND) 2021; 10:1121. [PMID: 34205907 PMCID: PMC8227383 DOI: 10.3390/plants10061121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/24/2021] [Accepted: 05/24/2021] [Indexed: 11/16/2022]
Abstract
Some grapevine rootstocks perform better than others during and after drought events, yet it is not clear how inherent and stress-induced differences in root morphology and anatomy along the length of fine roots are involved in these responses. Using a variety of growing conditions and plant materials, we observed significant differences in root diameter, specific root length (SRL) and root diameter distribution between two commonly used commercial grapevine rootstocks: Richter 110 (110R; drought resistant) and Millardet et de Grasset 101-14 (101-14Mgt; drought sensitive). The 110R consistently showed greater root diameters with smaller SRL and proportion of root length comprised of fine lateral roots. The 110R also exhibited significantly greater distance from tip to nearest lateral, longer white root length, and larger proportion of root length that is white under drought stress. Mapping of fine root cortical lacunae showed similar patterns between the rootstocks; mechanical failure of cortical cells was common in the maturation zone, limited near the root tip, and increased with drought stress for both genotypes; however, lacuna formed under wetter soil conditions in 110R. Results suggest that drought resistance in grapevine rootstocks is associated with thick, limitedly branched roots with a larger proportion of white-functional roots that tend to form lacuna under more mild water deficit, all of which likely favor continued resource acquisition at depth.
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Affiliation(s)
- Idan Reingwirtz
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Jake Uretsky
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Italo F. Cuneo
- Faculty of Agriculture and Food Sciences, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340025, Chile;
| | - Thorsten Knipfer
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
| | - Clarissa Reyes
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - M. Andrew Walker
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
| | - Andrew J. McElrone
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; (I.R.); (J.U.); (C.R.); (M.A.W.)
- Crops Pathology and Genetics Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616, USA
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Schenk HJ, Jansen S, Hölttä T. Positive pressure in xylem and its role in hydraulic function. THE NEW PHYTOLOGIST 2021; 230:27-45. [PMID: 33206999 DOI: 10.1111/nph.17085] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 10/13/2020] [Indexed: 05/29/2023]
Abstract
Although transpiration-driven transport of xylem sap is well known to operate under absolute negative pressure, many terrestrial, vascular plants show positive xylem pressure above atmospheric pressure on a seasonal or daily basis, or during early developmental stages. The actual location and mechanisms behind positive xylem pressure remain largely unknown, both in plants that show seasonal xylem pressure before leaf flushing, and those that show a diurnal periodicity of bleeding and guttation. Available evidence shows that positive xylem pressure can be driven based on purely physical forces, osmotic exudation into xylem conduits, or hydraulic pressure in parenchyma cells associated with conduits. The latter two mechanisms may not be mutually exclusive and can be understood based on a similar modelling scenario. Given the renewed interest in positive xylem pressure, this review aims to provide a constructive way forward by discussing similarities and differences of mechanistic models, evaluating available evidence for hydraulic functions, such as rehydration of tissues, refilling of water stores, and embolism repair under positive pressure, and providing recommendations for future research, including methods that avoid or minimise cutting artefacts.
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Affiliation(s)
- H Jochen Schenk
- Department of Biological Science, California State University Fullerton, PO Box 6850, Fullerton, CA, 92834, USA
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, PO Box 27, Helsinki, FI-00014, Finland
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Cuneo IF, Barrios-Masias F, Knipfer T, Uretsky J, Reyes C, Lenain P, Brodersen CR, Walker MA, McElrone AJ. Differences in grapevine rootstock sensitivity and recovery from drought are linked to fine root cortical lacunae and root tip function. THE NEW PHYTOLOGIST 2021; 229:272-283. [PMID: 32171020 DOI: 10.1111/nph.16542] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/05/2020] [Indexed: 06/10/2023]
Abstract
Structural changes during severe drought stress greatly modify the hydraulic properties of fine roots. Yet, the physiological basis behind the restoration of fine root water uptake capacity during water recovery remains unknown. Using neutron radiography (NR), X-ray micro-computed tomography (micro-CT), fluorescence microscopy, and fine root hydraulic conductivity measurements (Lpr ), we examined how drought-induced changes in anatomy and hydraulic properties of contrasting grapevine rootstocks are coupled with fine root growth dynamics during drought and return of soil moisture. Lacunae formation in drought-stressed fine roots was associated with a significant decrease in fine root Lpr for both rootstocks. However, lacunae formation occurred under milder stress in the drought-resistant rootstock, 110R. Suberin was deposited at an earlier developmental stage in fine roots of 101-14Mgt (i.e. drought susceptible), probably limiting cortical lacunae formation during mild stress. During recovery, we found that only 110R fine roots showed rapid re-establishment of elongation and water uptake capacity and we found that soil water status surrounding root tips differed between rootstocks as imaged with NR. These data suggest that drought resistance in grapevine rootstocks is associated with rapid re-establishment of growth and Lpr near the root tip upon re-watering by limiting competing sites along the root cylinder.
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Affiliation(s)
- Italo F Cuneo
- Department of Agriculture and Food Sciences, Pontificia Universidad Católica de Valparaíso, Valparaíso, 2340025, Chile
| | - Felipe Barrios-Masias
- Department of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, Reno, NV, 89557, USA
| | - Thorsten Knipfer
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
| | - Jake Uretsky
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
| | - Clarissa Reyes
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
| | - Pierre Lenain
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
| | - Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - M Andrew Walker
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, CA, 95618, USA
- Crops Pathology and Genetics Research Unit, USDA-ARS, Davis, CA, 95618, USA
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