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McLaughlin CM, Li M, Perryman M, Heymans A, Schneider H, Lasky JR, Sawers RJH. Evidence that variation in root anatomy contributes to local adaptation in Mexican native maize. Evol Appl 2024; 17:e13673. [PMID: 38468714 PMCID: PMC10925829 DOI: 10.1111/eva.13673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/07/2024] [Accepted: 02/22/2024] [Indexed: 03/13/2024] Open
Abstract
Mexican native maize (Zea mays ssp. mays) is adapted to a wide range of climatic and edaphic conditions. Here, we focus specifically on the potential role of root anatomical variation in this adaptation. Given the investment required to characterize root anatomy, we present a machine-learning approach using environmental descriptors to project trait variation from a relatively small training panel onto a larger panel of genotyped and georeferenced Mexican maize accessions. The resulting models defined potential biologically relevant clines across a complex environment that we used subsequently for genotype-environment association. We found evidence of systematic variation in maize root anatomy across Mexico, notably a prevalence of trait combinations favoring a reduction in axial hydraulic conductance in varieties sourced from cooler, drier highland areas. We discuss our results in the context of previously described water-banking strategies and present candidate genes that are associated with both root anatomical and environmental variation. Our strategy is a refinement of standard environmental genome-wide association analysis that is applicable whenever a training set of georeferenced phenotypic data is available.
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Affiliation(s)
- Chloee M. McLaughlin
- Intercollege Graduate Degree Program in Plant BiologyThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Meng Li
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Melanie Perryman
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Adrien Heymans
- Umeå Plant Science Centre, Department of Forest Genetics and Plant PhysiologySwedish University of Agricultural SciencesUmeåSweden
- Earth and Life InstituteUC LouvainLouvain‐la‐NeuveBelgium
| | - Hannah Schneider
- Department of Physiology and Cell BiologyLeibniz Institute for Plant Genetics and Crop Plant Research (IPK)SeelandGermany
| | - Jesse R. Lasky
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Ruairidh J. H. Sawers
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
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2
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Nasr Esfahani M, Sonnewald U. Unlocking dynamic root phenotypes for simultaneous enhancement of water and phosphorus uptake. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108386. [PMID: 38280257 DOI: 10.1016/j.plaphy.2024.108386] [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: 10/03/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 01/29/2024]
Abstract
Phosphorus (P) and water are crucial for plant growth, but their availability is challenged by climate change, leading to reduced crop production and global food security. In many agricultural soils, crop productivity is confronted by both water and P limitations. The diminished soil moisture decreases available P due to reduced P diffusion, and inadequate P availability diminishes tissue water status through modifications in stomatal conductance and a decrease in root hydraulic conductance. P and water display contrasting distributions in the soil, with P being concentrated in the topsoil and water in the subsoil. Plants adapt to water- and P-limited environments by efficiently exploring localized resource hotspots of P and water through the adaptation of their root system. Thus, developing cultivars with improved root architecture is crucial for accessing and utilizing P and water from arid and P-deficient soils. To meet this goal, breeding towards multiple advantageous root traits can lead to better cultivars for water- and P-limited environments. This review discusses the interplay of P and water availability and highlights specific root traits that enhance the exploration and exploitation of optimal resource-rich soil strata while reducing metabolic costs. We propose root ideotype models, including 'topsoil foraging', 'subsoil foraging', and 'topsoil/subsoil foraging' for maize (monocot) and common bean (dicot). These models integrate beneficial root traits and guide the development of water- and P-efficient cultivars for challenging environments.
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Affiliation(s)
- Maryam Nasr Esfahani
- Department of Biology, Chair of Biochemistry, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
| | - Uwe Sonnewald
- Department of Biology, Chair of Biochemistry, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
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3
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Wang R, Zhang Z, Wang H, Chen Y, Zhang M. Soil Water Deficit Reduced Root Hydraulic Conductivity of Common Reed ( Phragmites australis). PLANTS (BASEL, SWITZERLAND) 2023; 12:3543. [PMID: 37896007 PMCID: PMC10610267 DOI: 10.3390/plants12203543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/02/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023]
Abstract
Alterations in root hydraulics in response to varying moisture conditions remain a subject of debate. In our investigation, we subjected common reeds (Phragmites australis) to a 45-day treatment with four distinct soil moisture levels. The findings unveiled that, in response to drought stress, the total root length, surface area, volume, and average diameter exhibited varying degrees of reduction. Anatomically, drought caused a reduction in root diameter (RD), cortex thickness (CT), vessel diameter (VD), and root cross-sectional area (RCA). A decrease in soil moisture significantly reduced both whole- and single-root hydraulic conductivity (Lpwr, Lpsr). The total length, surface area, volume, and average diameter of the reed root system were significantly correlated with Lpwr, while RD, CT, and RCA were significantly correlated with Lpsr. A decrease in soil moisture content significantly influenced root morphological and anatomical characteristics, which, in turn, altered Lpr, and the transcriptome results suggest that this may be associated with the variation in the expression of abscisic acid (ABA) and aquaporins (AQPs) genes. Our initial findings address a gap in our understanding of reed hydraulics, offering fresh theoretical insights into how herbaceous plants respond to external stressors.
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Affiliation(s)
- Ruiqing Wang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; (R.W.); (H.W.)
- The Key Laboratory of Ecological Protection in the Yellow River Basin of National Forestry and Grassland Administration, Beijing 100083, China
- Wetland Research Centre, Beijing Forestry University, Beijing 100083, China
| | - Zhenming Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; (R.W.); (H.W.)
- The Key Laboratory of Ecological Protection in the Yellow River Basin of National Forestry and Grassland Administration, Beijing 100083, China
- Wetland Research Centre, Beijing Forestry University, Beijing 100083, China
| | - Haoyue Wang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; (R.W.); (H.W.)
- The Key Laboratory of Ecological Protection in the Yellow River Basin of National Forestry and Grassland Administration, Beijing 100083, China
- Wetland Research Centre, Beijing Forestry University, Beijing 100083, China
| | - Yinglong Chen
- The UWA Institute of Agriculture, School of Agriculture and Environment, The University of Western Australia, Perth, WA 6001, Australia;
| | - Mingxiang Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; (R.W.); (H.W.)
- The Key Laboratory of Ecological Protection in the Yellow River Basin of National Forestry and Grassland Administration, Beijing 100083, China
- State Key Laboratory of Efficient Production of Forest Resources, Beijing 100083, China
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4
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Liu L, Cui K, Qi X, Wu Y, Huang J, Peng S. Varietal responses of root characteristics to low nitrogen application explain the differing nitrogen uptake and grain yield in two rice varieties. FRONTIERS IN PLANT SCIENCE 2023; 14:1244281. [PMID: 37600168 PMCID: PMC10435752 DOI: 10.3389/fpls.2023.1244281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 07/18/2023] [Indexed: 08/22/2023]
Abstract
Rice root characteristics are tightly associated with high-efficient nitrogen uptake. To understand the relationship of root plastic responses with nitrogen uptake when reducing nitrogen application for green rice production, a hydroponic experiment and a soil pot experiment were conducted under high (HN) and low (LN) nitrogen applications, using two rice (Oryza sativa L.) varieties, NK57 and YD6, three nitrogen absorption traits (total nitrogen accumulation, net NH4 + influx on root surface, nitrogen uptake via apoplasmic pathway) and root characteristics were investigated. In comparison with HN, LN significantly reduced nitrogen absorption and grain yield in both varieties. Concomitantly, there was a decrease in total root length, root surface area, root number, root volume, and root cortical area under LN, while single root length, root aerenchyma area, and root lignin content increased. The expression of OsAMT1;1 and OsAMT1;2 down-regulated in both varieties. The findings revealed that YD6 had smaller reduction degree for the three nitrogen absorption traits and grain yield, accompanied by smaller reduction degree in total root length, root surface area, root cortical area, and expression of the two genes under LN. These root characteristics were significantly and positively correlated with the three nitrogen absorption traits and grain yield, especially under LN. These results indicate that a large root system, lower reduction degree in several root characters, and high expression of OsAMT genes in YD6 explains its high nitrogen accumulation and grain yield under reduced nitrogen application. The study may provide rationale for developing varieties with low nitrogen fertilizer requirements for enabling green rice production.
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Affiliation(s)
- Lei Liu
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Kehui Cui
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiaoli Qi
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yu Wu
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jianliang Huang
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shaobing Peng
- National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China
- Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
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Li J, Le X, Chen X, Niklas KJ, Li X, Wu P, Zhou Y, Zhong Q, Hu D, Cheng D. The allocation of anatomical traits determines the trade-off between fine root resource acquisition-transport function. Oecologia 2023; 202:845-854. [PMID: 37624444 DOI: 10.1007/s00442-023-05443-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023]
Abstract
Cortex radius (CR) and stele radius (SR) are important functional traits associated with the nutrient acquisition and transport functions of fine roots, respectively. However, for developmental and anatomical reasons, the resource acquisition-transport relationship of fine roots is expected to be different for different root orders. To address this issue, critical fine root anatomical traits were examined for the first three orders of roots of 59 subtropical woody plants. Designating the most distal fine roots as order one, SR scaled isometrically with respect to root radius (RR) (i.e., SR ∝ RR1.0) in the three root orders, whereas CR scaled allometrically with respect to RR (i.e., CR ∝ RR>1.0) with the numerical values of scaling exponents increasing significantly with increasing root orders thereby indicating a disproportional increase in CR with increasing root orders. There were also differences between normalized root tissue (CR/RR and SR/RR) and RR in different root orders. A negative isometric relationship (i.e., SR/RR ∝ RR-1.0) existed between SR/RR and RR in three order roots, whereas the allometric exponent between CR/RR and RR increased with root order (from 0.88 to 1.55). Collectively, the data indicate that root anatomical and functional traits change as a function of RR and that these changes need to be considered when modeling fine root resource acquisition-transport functions.
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Affiliation(s)
- Jinlong Li
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Xingui Le
- Yangjifeng National Nature Reserve Administration of Jiangxi Province, Jiangxi, China
| | - Xiaoping Chen
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, China
| | - Karl J Niklas
- School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Xueqin Li
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Panpan Wu
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Yongjiao Zhou
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Quanlin Zhong
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Dandan Hu
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China
| | - Dongliang Cheng
- Institute of Geography, School of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian, China.
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, China.
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6
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Rishmawi L, Bauget F, Protto V, Bauland C, Nacry P, Maurel C. Natural variation of maize root hydraulic architecture underlies highly diverse water uptake capacities. PLANT PHYSIOLOGY 2023; 192:2404-2418. [PMID: 37052178 PMCID: PMC10315320 DOI: 10.1093/plphys/kiad213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Plant water uptake is determined by the root system architecture and its hydraulic capacity, which together define the root hydraulic architecture. The current research aims at understanding the water uptake capacities of maize (Zea mays), a model organism and major crop. We explored the genetic variations within a collection of 224 maize inbred Dent lines and successively defined core genotype subsets to access multiple architectural, anatomical, and hydraulic parameters in the primary root (PR) and seminal roots (SR) of hydroponically grown seedlings. We found 9-, 3.5-, and 12.4-fold genotypic differences for root hydraulics (Lpr), PR size, and lateral root size, respectively, that shaped wide and independent variations of root structure and function. Within genotypes, PR and SR showed similarities in hydraulics and, to a lesser extent, in anatomy. They had comparable aquaporin activity profiles that, however, could not be explained by aquaporin expression levels. Genotypic variations in the size and number of late meta xylem vessels were positively correlated with Lpr. Inverse modeling further revealed dramatic genotypic differences in the xylem conductance profile. Thus, tremendous natural variation of maize root hydraulic architecture underlies a high diversity of water uptake strategies and paves the way to quantitative genetic dissection of its elementary traits.
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Affiliation(s)
- Louai Rishmawi
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France
| | - Fabrice Bauget
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France
| | - Virginia Protto
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France
| | - Cyril Bauland
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE—Le Moulon, Gif-sur-Yvette, France
| | - Philippe Nacry
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France
| | - Christophe Maurel
- IPSiM, Univ Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France
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Ning J, Yamauchi T, Takahashi H, Omori F, Mano Y, Nakazono M. Asymmetric auxin distribution establishes a contrasting pattern of aerenchyma formation in the nodal roots of Zea nicaraguensis during gravistimulation. FRONTIERS IN PLANT SCIENCE 2023; 14:1133009. [PMID: 37152158 PMCID: PMC10154625 DOI: 10.3389/fpls.2023.1133009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/28/2023] [Indexed: 05/09/2023]
Abstract
Auxin distribution is essential for determining root developmental patterns. The formation of lateral roots and constitutive aerenchyma, which is a gas space developed through cell death, is regulated by auxin in rice (Oryza sativa). However, it is unclear whether the involvement of auxin in constitutive aerenchyma formation is conserved in other species. In this study, we found that constitutive aerenchyma formation was regulated by auxin in the nodal roots of Zea nicaraguensis, a wild relative of maize (Zea mays ssp. mays) grown naturally on frequently flooded coastal plains. Subsequent gravistimulation (root rotation) experiments showed opposite patterns of aerenchyma and lateral root formation. Lateral root formation on the convex side of rotated roots is known to be stimulated by a transient increase in auxin level in the pericycle. We found that aerenchyma formation was accelerated in the cortex on the concave side of the rotated nodal roots of Z. nicaraguensis. A cortex-specific expression analysis of auxin-responsive genes suggested that the auxin level was higher on the concave side than on the convex side. These results suggest that asymmetric auxin distribution underlies the regulation of aerenchyma and lateral root formation in the nodal roots of Z. nicaraguensis. As aerenchyma reduces the respiratory cost of the roots, constitutive aerenchyma on the concave side of the nodal root may balance resource allocation, thereby contributing to the uptake of water and nutrients by newly formed lateral roots. Our study provides insights into auxin-dependent asymmetric root patterning such as that of gravistimulation and hydropatterning response.
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Affiliation(s)
- Jiayang Ning
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Takaki Yamauchi
- Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi, Japan
| | - Hirokazu Takahashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Fumie Omori
- Division of Feed and Livestock Research, National Agriculture and Food Research Organization (NARO) Institute of Livestock and Grassland Science, Nasushiobara, Tochigi, Japan
| | - Yoshiro Mano
- Division of Feed and Livestock Research, National Agriculture and Food Research Organization (NARO) Institute of Livestock and Grassland Science, Nasushiobara, Tochigi, Japan
| | - Mikio Nakazono
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan
- The University of Western Australia (UWA) School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
- *Correspondence: Mikio Nakazono,
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8
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Schneider HM. Functional implications of multiseriate cortical sclerenchyma for soil resource capture and crop improvement. AOB PLANTS 2022; 14:plac050. [PMID: 36545297 PMCID: PMC9762723 DOI: 10.1093/aobpla/plac050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/17/2022] [Indexed: 06/09/2023]
Abstract
Suboptimal nutrient and water availability are primary constraints to crop growth. Global agriculture requires crops with greater nutrient and water efficiency. Multiseriate cortical sclerenchyma (MCS), a root anatomical trait characterized by small cells with thick cell walls encrusted with lignin in the outer cortex, has been shown to be an important trait for adaptation in maize and wheat in mechanically impeded soils. However, MCS has the potential to improve edaphic stress tolerance in a number of different crop taxa and in a number of different environments. This review explores the functional implications of MCS as an adaptive trait for water and nutrient acquisition and discusses future research perspectives on this trait for incorporation into crop breeding programs. For example, MCS may influence water and nutrient uptake, resistance to pests, symbiotic interactions, microbial interactions in the rhizosphere and soil carbon deposition. Root anatomical phenotypes are underutilized; however, important breeding targets for the development of efficient, productive and resilient crops urgently needed in global agriculture.
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Siangliw JL, Thunnom B, Natividad MA, Quintana MR, Chebotarov D, McNally KL, Lynch JP, Brown KM, Henry A. Response of Southeast Asian rice root architecture and anatomy phenotypes to drought stress. FRONTIERS IN PLANT SCIENCE 2022; 13:1008954. [PMID: 36340400 PMCID: PMC9629509 DOI: 10.3389/fpls.2022.1008954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Drought stress in Southeast Asia greatly affects rice production, and the rice root system plays a substantial role in avoiding drought stress. In this study, we examined the phenotypic and genetic correlations among root anatomical, morphological, and agronomic phenotypes over multiple field seasons. A set of >200 rice accessions from Southeast Asia (a subset of the 3000 Rice Genomes Project) was characterized with the aim to identify root morphological and anatomical phenotypes related to productivity under drought stress. Drought stress resulted in slight increases in the basal metaxylem and stele diameter of nodal roots. Although few direct correlations between root phenotypes and grain yield were identified, biomass was consistently positively correlated with crown root number and negatively correlated with stele diameter. The accessions with highest grain yield were characterized by higher crown root numbers and median metaxylem diameter and smaller stele diameter. Genome-wide association study (GWAS) revealed 162 and 210 significant SNPs associated with root phenotypes in the two seasons which resulted in identification of 59 candidate genes related to root development. The gene OsRSL3 was found in a QTL region for median metaxylem diameter. Four SNPs in OsRSL3 were found that caused amino acid changes and significantly associated with the root phenotype. Based on the haplotype analysis for median metaxylem diameter, the rice accessions studied were classified into five allele combinations in order to identify the most favorable haplotypes. The candidate genes and favorable haplotypes provide information useful for the genetic improvement of root phenotypes under drought stress.
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Affiliation(s)
- Jonaliza L. Siangliw
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Burin Thunnom
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Mignon A. Natividad
- Rice Breeding Innovations Platform, International Rice Research Institute, Los Baños, Philippines
| | - Marinell R. Quintana
- Rice Breeding Innovations Platform, International Rice Research Institute, Los Baños, Philippines
| | - Dmytro Chebotarov
- Rice Breeding Innovations Platform, International Rice Research Institute, Los Baños, Philippines
| | - Kenneth L. McNally
- Rice Breeding Innovations Platform, International Rice Research Institute, Los Baños, Philippines
| | - Jonathan P. Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
| | - Kathleen M. Brown
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
| | - Amelia Henry
- Rice Breeding Innovations Platform, International Rice Research Institute, Los Baños, Philippines
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10
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Clément C, Schneider HM, Dresbøll DB, Lynch JP, Thorup-Kristensen K. Root and xylem anatomy varies with root length, root order, soil depth and environment in intermediate wheatgrass (Kernza®) and alfalfa. ANNALS OF BOTANY 2022; 130:367-382. [PMID: 35468194 PMCID: PMC9486898 DOI: 10.1093/aob/mcac058] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/25/2022] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND AIMS Deep roots (i.e. >1 m depth) are important for crops to access water when the topsoil is dry. Root anatomy and hydraulic conductance play important roles in the uptake of soil water, particularly water located deep in the soil. We investigated whether root and xylem anatomy vary as a function of root type, order and length, or with soil depth in roots of two deep-rooted perennial crops: intermediate wheatgrass [Thinopyrum intermedium (Kernza®)] and alfalfa (Medicago sativa). We linked the expression of these anatomical traits to the plants' capacity to take up water from deep soil layers. METHODS Using laser ablation tomography, we compared the roots of the two crops for cortical area, number and size of metaxylem vessels, and their estimated root axial hydraulic conductance (ERAHCe). The deepest roots investigated were located at soil depths of 2.25 and at 3.5 m in the field and in rhizoboxes, respectively. Anatomical differences were characterized along 1-m-long individual roots, among root types and orders, as well as between environmental conditions. KEY RESULTS For both crops, a decrease in the number and diameter, or both, of metaxylem vessels along individual root segments and with soil depth in the field resulted in a decrease in ERAHCe. Alfalfa, with a greater number of metaxylem vessels per root throughout the soil profile and, on average, a 4-fold greater ERAHCe, took up more water from the deep soil layers than intermediate wheatgrass. Root anatomical traits were significantly different across root types, classes and growth conditions. CONCLUSIONS Root anatomical traits are important tools for the selection of crops with enhanced exploitation of deep soil water. The development and breeding of perennial crops for improved subsoil exploitation will be aided by greater understanding of root phenotypes linked to deep root growth and activity.
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Affiliation(s)
| | - Hannah M Schneider
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802, USA
| | - Dorte Bodin Dresbøll
- Department of Plant and Environmental Science, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Jonathan P Lynch
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802, USA
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11
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Jayabalan S, Rajakani R, Kumari K, Pulipati S, Hariharan RVG, Venkatesan SD, Jaganathan D, Kancharla PK, Raju K, Venkataraman G. Morpho-physiological, biochemical and molecular characterization of coastal rice landraces to identify novel genetic sources of salinity tolerance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 187:50-66. [PMID: 35952550 DOI: 10.1016/j.plaphy.2022.07.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 07/01/2022] [Accepted: 07/24/2022] [Indexed: 06/15/2023]
Abstract
Soil salinity is a leading cause for yield losses in rice, affecting nearly 6% of global rice cultivable area. India is host to a rich diversity of coastal rice landraces that are naturally tolerant to salinity and an untapped source to identify novel determinants of salinity tolerance. In the present study, we have assessed the relative salinity tolerance of 43 previously genotyped rice landraces at seedling stage, using thirteen morpho-physiological and biochemical parameters using a hydroponics system. Among 43 rice varieties, 25 were tolerant, 15 were moderately tolerant, 1 was moderately susceptible and 2 sensitive checks were found to be highly susceptible based on standard salinity scoring methods. In addition to previously known saline tolerant genotypes (Pokkali, FL478 and Nona Bokra), the present study has novel genotypes such as Katrangi, Orkyma, Aduisen 1, Orumundakan 1, Hoogla, and Talmugur 2 as potential sources of salinity tolerance through measurement of morpho-physiological and biochemical parameters including Na+, K+ estimations and Na+/K+ ratios. Further, Pallipuram Pokkali may be an important source of the tissue tolerance trait under salinity. Four marker trait associations (RM455-root Na+; RM161-shoot and root Na+/K+ ratios; RM237-salinity tolerance index) accounted for phenotypic variations in the range of 20.97-39.82%. A significant increase in root endodermal and exodermal suberization was observed in selected rice landraces under salinity. For the first time, variation in the number of suberized sclerenchymatous layers as well as passage cells is reported, in addition to expression level changes in suberin biosynthetic genes (CYP86A2, CYP81B1, CYP86A8 and PERL).
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Affiliation(s)
- Shilpha Jayabalan
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India; Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Raja Rajakani
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India
| | - Kumkum Kumari
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India
| | - Shalini Pulipati
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India
| | - Raj V Ganesh Hariharan
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, Kancheepuram, 603203, Tamil Nadu, India
| | - Sowmiya Devi Venkatesan
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, Kancheepuram, 603203, Tamil Nadu, India
| | - Deepa Jaganathan
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India; Department of Plant Biotechnology, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore, 641003, Tamil Nadu, India
| | - Pavan Kumar Kancharla
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, 605014, India
| | - Kalaimani Raju
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India
| | - Gayatri Venkataraman
- Plant Molecular Biology Laboratory, Department of Biotechnology, M. S. Swaminathan Research Foundation (MSSRF), Taramani, Chennai, 600113, Tamil Nadu, India.
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12
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Xu H, Wang S, Tang L, Wang Y, Li Z, Wang W. Differential influence of cortex and stele components on root tip diameter in different types of tropical climbing plants. FRONTIERS IN PLANT SCIENCE 2022; 13:961214. [PMID: 36119575 PMCID: PMC9470880 DOI: 10.3389/fpls.2022.961214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Climbing plants are an abundant and taxonomically diverse plant group that competes intensely with trees and thus substantially affects forest diversity and structure. The growth and physiology of climbing plants largely depend on their root tip structure and function. However, little is known regarding the mechanisms through which anatomical traits regulate root tip diameter in climbing plants. Therefore, our study sought to explore the relationships between root tip diameter and seven anatomical traits (e.g., cortex thickness and stele diameter) in three lianas and three vine species sampled from a tropical forest in Hainan. Root tip diameter was significantly positively correlated with cortex thickness (r = 0.94-0.99) and stele diameter (r = 0.72-0.94) within species, especially with cortex thickness. Cortex thickness was significantly positively correlated with mean cortical cell diameter in six species (r = 0.72-0.93), but was only correlated with the number of cortical cell layers in three species (r = 0.42-0.66). Stele diameter displayed significant positive correlations with mean conduit diameter (r = 0.58-0.88) and the number of conduits per stele (r = 0.50-0.66, except for Cyclea hypoglauca), and was negatively correlated with conduit density in all species (r = -0.65 to -0.77). The correlations between cortical cells and conduit traits and root tip diameter were similar to that with cortex thickness and stele diameter, respectively. Compared with vines, liana root tips showed closer relationships between root diameter and cortex thickness and stele diameter, and between cortex thickness and mean diameter of cortical cells. Moreover, the root tip of lianas possesses significantly higher stele proportion and denser conduits, significantly lower cortex proportion, and smaller conduit size than those of vines. However, the specific conductivity was similar. Overall, these results suggest that the cortex is the main driver for the change in root tip diameter rather than the stele. Nevertheless, both factors were responsible for variations in diameter-related traits when compared with number-related traits, with lianas and vines exhibiting distinct regulatory mechanisms.
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Affiliation(s)
- Haiwu Xu
- Key Laboratory of Germplasm Resources of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, China
| | - Siyuan Wang
- School of Forestry, Northeast Forestry University, Harbin, China
| | - Liang Tang
- Key Laboratory of Germplasm Resources of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, China
| | - Yan Wang
- Taishan Forest Ecosystem Research Station of State Forestry Administration, State Forestry and Grassland Administration Key Laboratory of Silviculture in downstream areas of the Yellow River, College of Forestry, Shandong Agricultural University, Taian, China
| | - Zhongyue Li
- Taishan Forest Ecosystem Research Station of State Forestry Administration, State Forestry and Grassland Administration Key Laboratory of Silviculture in downstream areas of the Yellow River, College of Forestry, Shandong Agricultural University, Taian, China
| | - Wenna Wang
- Key Laboratory of Germplasm Resources of Tropical Special Ornamental Plants of Hainan Province, College of Forestry, Hainan University, Haikou, China
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13
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Zhou M, Guo Y, Sheng J, Yuan Y, Zhang WH, Bai W. Using anatomical traits to understand root functions across root orders of herbaceous species in a temperate steppe. THE NEW PHYTOLOGIST 2022; 234:422-434. [PMID: 35048364 DOI: 10.1111/nph.17978] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
Root anatomical traits play crucial roles in understanding root functions and root form-function linkages. However, the root anatomy and form-function linkages of monocotyledonous and dicotyledonous herbs remain largely unknown. We measured order-based anatomical traits and mycorrhizal colonization rates of 32 perennial herbs of monocotyledons and dicotyledons in a temperate steppe. For monocots, relative constant proportion of cortex and mycorrhizal colonization rates, but increased cell-wall thickening of the endodermis and proportion of stele were observed across root orders, indicating a slight reduction in absorption capacity and improvement in transportation capacity across orders. For dicots, the cortex and mycorrhizal colonization disappeared in the fourth-order and/or fifth-order roots, whereas the secondary vascular tissue increased markedly, suggesting significant transition of root functions from absorption to transportation across root orders. The allometric relationships between stele and cortex differed across root orders and plant groups, suggesting different strategies to coordinate the absorption and transportation functions among plant groups. In summary, our results revealed different functional transition patterns across root orders and distinct strategies for coordinating the absorption and transportation of root system between monocots and dicots. These findings will contribute to our understanding of the root form and functions in herbaceous species.
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Affiliation(s)
- Meng Zhou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
| | - Yumeng Guo
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Sheng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yujia Yuan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wen-Hao Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenming Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
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14
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Cai G, Ahmed MA, Abdalla M, Carminati A. Root hydraulic phenotypes impacting water uptake in drying soils. PLANT, CELL & ENVIRONMENT 2022; 45:650-663. [PMID: 35037263 PMCID: PMC9303794 DOI: 10.1111/pce.14259] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 05/11/2023]
Abstract
Soil drying is a limiting factor for crop production worldwide. Yet, it is not clear how soil drying impacts water uptake across different soils, species, and root phenotypes. Here we ask (1) what root phenotypes improve the water use from drying soils? and (2) what root hydraulic properties impact water flow across the soil-plant continuum? The main objective is to propose a hydraulic framework to investigate the interplay between soil and root hydraulic properties on water uptake. We collected highly resolved data on transpiration, leaf and soil water potential across 11 crops and 10 contrasting soil textures. In drying soils, the drop in water potential at the soil-root interface resulted in a rapid decrease in soil hydraulic conductance, especially at higher transpiration rates. The analysis reveals that water uptake was limited by soil within a wide range of soil water potential (-6 to -1000 kPa), depending on both soil textures and root hydraulic phenotypes. We propose that a root phenotype with low root hydraulic conductance, long roots and/or long and dense root hairs postpones soil limitation in drying soils. The consequence of these root phenotypes on crop water use is discussed.
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Affiliation(s)
- Gaochao Cai
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Mutez A. Ahmed
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
- Department of Land, Air and Water ResourcesUniversity of California DavisDavisCaliforniaUnited States
| | - Mohanned Abdalla
- Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Andrea Carminati
- Department of Environmental Systems Science, Physics of Soils and Terrestrial EcosystemsInstitute of Terrestrial Ecosystems, ETH ZürichZurichSwitzerland
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15
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Lynch JP, Mooney SJ, Strock CF, Schneider HM. Future roots for future soils. PLANT, CELL & ENVIRONMENT 2022; 45:620-636. [PMID: 34725839 PMCID: PMC9299599 DOI: 10.1111/pce.14213] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/05/2021] [Accepted: 10/06/2021] [Indexed: 05/12/2023]
Abstract
Mechanical impedance constrains root growth in most soils. Crop cultivation changed the impedance characteristics of native soils, through topsoil erosion, loss of organic matter, disruption of soil structure and loss of biopores. Increasing adoption of Conservation Agriculture in high-input agroecosystems is returning cultivated soils to the soil impedance characteristics of native soils, but in the low-input agroecosystems characteristic of developing nations, ongoing soil degradation is generating more challenging environments for root growth. We propose that root phenotypes have evolved to adapt to the altered impedance characteristics of cultivated soil during crop domestication. The diverging trajectories of soils under Conservation Agriculture and low-input agroecosystems have implications for strategies to develop crops to meet global needs under climate change. We present several root ideotypes as breeding targets under the impedance regimes of both high-input and low-input agroecosystems, as well as a set of root phenotypes that should be useful in both scenarios. We argue that a 'whole plant in whole soil' perspective will be useful in guiding the development of future crops for future soils.
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Affiliation(s)
- Jonathan P. Lynch
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Sacha J. Mooney
- School of BiosciencesUniversity of NottinghamLeicestershireUK
| | - Christopher F. Strock
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Hannah M. Schneider
- Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
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16
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Siqueira JA, Otoni WC, Araújo WL. The hidden half comes into the spotlight: Peeking inside the black box of root developmental phases. PLANT COMMUNICATIONS 2022; 3:100246. [PMID: 35059627 PMCID: PMC8760039 DOI: 10.1016/j.xplc.2021.100246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/13/2021] [Accepted: 09/18/2021] [Indexed: 05/30/2023]
Abstract
Efficient use of natural resources (e.g., light, water, and nutrients) can be improved with a tailored developmental program that maximizes the lifetime and fitness of plants. In plant shoots, a developmental phase represents a time window in which the meristem triggers the development of unique morphological and physiological traits, leading to the emergence of leaves, flowers, and fruits. Whereas developmental phases in plant shoots have been shown to enhance food production in crops, this phenomenon has remained poorly investigated in roots. In light of recent advances, we suggest that root development occurs in three main phases: root apical meristem appearance, foraging, and senescence. We provide compelling evidence suggesting that these phases are regulated by at least four developmental pathways: autonomous, non-autonomous, hormonal, and periodic. Root developmental pathways differentially coordinate organ plasticity, promoting morphological alterations, tissue regeneration, and cell death regulation. Furthermore, we suggest how nutritional checkpoints may allow progression through the developmental phases, thus completing the root life cycle. These insights highlight novel and exciting advances in root biology that may help maximize the productivity of crops through more sustainable agriculture and the reduced use of chemical fertilizers.
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17
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Huang C, Butterly CR, Moody D, Pourkheirandish M. Mini review: Targeting below-ground plant performance to improve nitrogen use efficiency (NUE) in barley. Front Genet 2022; 13:1060304. [PMID: 36935938 PMCID: PMC10017981 DOI: 10.3389/fgene.2022.1060304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/19/2022] [Indexed: 03/06/2023] Open
Abstract
Nitrogen (N) fertilizer is one of the major inputs for grain crops including barley and its usage is increasing globally. However, N use efficiency (NUE) is low in cereal crops, leading to higher production costs, unfulfilled grain yield potential and environmental hazards. N uptake is initiated from plant root tips but a very limited number of studies have been conducted on roots relevant to NUE specifically. In this review, we used barley, the fourth most important cereal crop, as the primary study plant to investigate this topic. We first highlighted the recent progress and study gaps in genetic analysis results, primarily, the genome-wide association study (GWAS) regarding both biological and statistical considerations. In addition, different factors contributing to NUE are discussed in terms of root morphological and anatomical traits, as well as physiological mechanisms such as N transporter activities and hormonal regulation.
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Affiliation(s)
- Claire Huang
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Clayton R. Butterly
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, VIC, Australia
- *Correspondence: Clayton R. Butterly, ; Mohammad Pourkheirandish,
| | - David Moody
- InterGrain Pty Ltd., Bibra Lake, WA, Australia
| | - Mohammad Pourkheirandish
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, VIC, Australia
- *Correspondence: Clayton R. Butterly, ; Mohammad Pourkheirandish,
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18
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Lynch JP. Harnessing root architecture to address global challenges. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:415-431. [PMID: 34724260 PMCID: PMC9299910 DOI: 10.1111/tpj.15560] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 05/06/2023]
Abstract
Root architecture can be targeted in breeding programs to develop crops with better capture of water and nutrients. In rich nations, such crops would reduce production costs and environmental pollution and, in developing nations, they would improve food security and economic development. Crops with deeper roots would have better climate resilience while also sequestering atmospheric CO2 . Deeper rooting, which improves water and N capture, is facilitated by steeper root growth angles, fewer axial roots, reduced lateral branching, and anatomical phenotypes that reduce the metabolic cost of root tissue. Mechanical impedance, hypoxia, and Al toxicity are constraints to subsoil exploration. To improve topsoil foraging for P, K, and other shallow resources, shallower root growth angles, more axial roots, and greater lateral branching are beneficial, as are metabolically cheap roots. In high-input systems, parsimonious root phenotypes that focus on water capture may be advantageous. The growing prevalence of Conservation Agriculture is shifting the mechanical impedance characteristics of cultivated soils in ways that may favor plastic root phenotypes capable of exploiting low resistance pathways to the subsoil. Root ideotypes for many low-input systems would not be optimized for any one function, but would be resilient against an array of biotic and abiotic challenges. Root hairs, reduced metabolic cost, and developmental regulation of plasticity may be useful in all environments. The fitness landscape of integrated root phenotypes is large and complex, and hence will benefit from in silico tools. Understanding and harnessing root architecture for crop improvement is a transdisciplinary opportunity to address global challenges.
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Affiliation(s)
- Jonathan P. Lynch
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPA16802USA
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19
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Guo H, Ayalew H, Seethepalli A, Dhakal K, Griffiths M, Ma X, York LM. Functional phenomics and genetics of the root economics space in winter wheat using high-throughput phenotyping of respiration and architecture. THE NEW PHYTOLOGIST 2021; 232:98-112. [PMID: 33683730 PMCID: PMC8518983 DOI: 10.1111/nph.17329] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/26/2021] [Indexed: 05/05/2023]
Abstract
The root economics space is a useful framework for plant ecology but is rarely considered for crop ecophysiology. In order to understand root trait integration in winter wheat, we combined functional phenomics with trait economic theory, utilizing genetic variation, high-throughput phenotyping, and multivariate analyses. We phenotyped a diversity panel of 276 genotypes for root respiration and architectural traits using a novel high-throughput method for CO2 flux and the open-source software RhizoVision Explorer to analyze scanned images. We uncovered substantial variation in specific root respiration (SRR) and specific root length (SRL), which were primary indicators of root metabolic and structural costs. Multiple linear regression analysis indicated that lateral root tips had the greatest SRR, and the residuals from this model were used as a new trait. Specific root respiration was negatively correlated with plant mass. Network analysis, using a Gaussian graphical model, identified root weight, SRL, diameter, and SRR as hub traits. Univariate and multivariate genetic analyses identified genetic regions associated with SRR, SRL, and root branching frequency, and proposed gene candidates. Combining functional phenomics and root economics is a promising approach to improving our understanding of crop ecophysiology. We identified root traits and genomic regions that could be harnessed to breed more efficient crops for sustainable agroecosystems.
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Affiliation(s)
- Haichao Guo
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Habtamu Ayalew
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
| | | | - Kundan Dhakal
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Marcus Griffiths
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Xue‐Feng Ma
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Larry M. York
- Noble Research Institute LLC2510 Sam Noble ParkwayArdmoreOK73401USA
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20
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Guo H, Ayalew H, Seethepalli A, Dhakal K, Griffiths M, Ma XF, York LM. Functional phenomics and genetics of the root economics space in winter wheat using high-throughput phenotyping of respiration and architecture. THE NEW PHYTOLOGIST 2021. [PMID: 33683730 DOI: 10.1101/2020.11.12.380238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The root economics space is a useful framework for plant ecology but is rarely considered for crop ecophysiology. In order to understand root trait integration in winter wheat, we combined functional phenomics with trait economic theory, utilizing genetic variation, high-throughput phenotyping, and multivariate analyses. We phenotyped a diversity panel of 276 genotypes for root respiration and architectural traits using a novel high-throughput method for CO2 flux and the open-source software RhizoVision Explorer to analyze scanned images. We uncovered substantial variation in specific root respiration (SRR) and specific root length (SRL), which were primary indicators of root metabolic and structural costs. Multiple linear regression analysis indicated that lateral root tips had the greatest SRR, and the residuals from this model were used as a new trait. Specific root respiration was negatively correlated with plant mass. Network analysis, using a Gaussian graphical model, identified root weight, SRL, diameter, and SRR as hub traits. Univariate and multivariate genetic analyses identified genetic regions associated with SRR, SRL, and root branching frequency, and proposed gene candidates. Combining functional phenomics and root economics is a promising approach to improving our understanding of crop ecophysiology. We identified root traits and genomic regions that could be harnessed to breed more efficient crops for sustainable agroecosystems.
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Affiliation(s)
- Haichao Guo
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Habtamu Ayalew
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Anand Seethepalli
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Kundan Dhakal
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Marcus Griffiths
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Xue-Feng Ma
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Larry M York
- Noble Research Institute LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
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21
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Li X, Marquardt A, Wasson A. Carbon budgeting belowground. THE NEW PHYTOLOGIST 2021; 232:5-7. [PMID: 34216155 DOI: 10.1111/nph.17520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Xiaoqing Li
- CSIRO Agriculture & Food, Black Mountain, Canberra, ACT, 2601, Australia
| | | | - Anton Wasson
- CSIRO Agriculture & Food, St Lucia, Brisbane, QLD, 4067, Australia
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22
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Burak E, Quinton JN, Dodd IC. Root hairs are the most important root trait for rhizosheath formation of barley (Hordeum vulgare), maize (Zea mays) and Lotus japonicus (Gifu). ANNALS OF BOTANY 2021; 128:45-57. [PMID: 33631013 PMCID: PMC8318254 DOI: 10.1093/aob/mcab029] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 03/15/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Rhizosheaths are defined as the soil adhering to the root system after it is extracted from the ground. Root hairs and mucilage (root exudates) are key root traits involved in rhizosheath formation, but to better understand the mechanisms involved their relative contributions should be distinguished. METHODS The ability of three species [barley (Hordeum vulgare), maize (Zea mays) and Lotus japonicus (Gifu)] to form a rhizosheath in a sandy loam soil was compared with that of their root-hairless mutants [bald root barley (brb), maize root hairless 3 (rth3) and root hairless 1 (Ljrhl1)]. Root hair traits (length and density) of wild-type (WT) barley and maize were compared along with exudate adhesiveness of both barley and maize genotypes. Furthermore, root hair traits and exudate adhesiveness from different root types (axile versus lateral) were compared within the cereal species. KEY RESULTS Per unit root length, rhizosheath size diminished in the order of barley > L. japonicus > maize in WT plants. Root hairs significantly increased rhizosheath formation of all species (3.9-, 3.2- and 1.8-fold for barley, L. japonicus and maize, respectively) but there was no consistent genotypic effect on exudate adhesiveness in the cereals. While brb exudates were more and rth3 exudates were less adhesive than their respective WTs, maize rth3 bound more soil than barley brb. Although both maize genotypes produced significantly more adhesive exudate than the barley genotypes, root hair development of WT barley was more extensive than that of WT maize. Thus, the greater density of longer root hairs in WT barley bound more soil than WT maize. Root type did not seem to affect rhizosheath formation, unless these types differed in root length. CONCLUSIONS When root hairs were present, greater root hair development better facilitated rhizosheath formation than root exudate adhesiveness. However, when root hairs were absent root exudate adhesiveness was a more dominant trait.
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Affiliation(s)
- Emma Burak
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - John N Quinton
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Ian C Dodd
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
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23
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Schneider HM, Strock CF, Hanlon MT, Vanhees DJ, Perkins AC, Ajmera IB, Sidhu JS, Mooney SJ, Brown KM, Lynch JP. Multiseriate cortical sclerenchyma enhance root penetration in compacted soils. Proc Natl Acad Sci U S A 2021; 118:e2012087118. [PMID: 33536333 PMCID: PMC8017984 DOI: 10.1073/pnas.2012087118] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mechanical impedance limits soil exploration and resource capture by plant roots. We examine the role of root anatomy in regulating plant adaptation to mechanical impedance and identify a root anatomical phene in maize (Zea mays) and wheat (Triticum aestivum) associated with penetration of hard soil: Multiseriate cortical sclerenchyma (MCS). We characterize this trait and evaluate the utility of MCS for root penetration in compacted soils. Roots with MCS had a greater cell wall-to-lumen ratio and a distinct UV emission spectrum in outer cortical cells. Genome-wide association mapping revealed that MCS is heritable and genetically controlled. We identified a candidate gene associated with MCS. Across all root classes and nodal positions, maize genotypes with MCS had 13% greater root lignin concentration compared to genotypes without MCS. Genotypes without MCS formed MCS upon exogenous ethylene exposure. Genotypes with MCS had greater lignin concentration and bending strength at the root tip. In controlled environments, MCS in maize and wheat was associated improved root tensile strength and increased penetration ability in compacted soils. Maize genotypes with MCS had root systems with 22% greater depth and 49% greater shoot biomass in compacted soils in the field compared to lines without MCS. Of the lines we assessed, MCS was present in 30 to 50% of modern maize, wheat, and barley cultivars but was absent in teosinte and wild and landrace accessions of wheat and barley. MCS merits investigation as a trait for improving plant performance in maize, wheat, and other grasses under edaphic stress.
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Affiliation(s)
- Hannah M Schneider
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Christopher F Strock
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Meredith T Hanlon
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Dorien J Vanhees
- Division of Agricultural and Environment Sciences, School of Biosciences, University of Nottingham, Leicestershire LE12 5RD, United Kingdom
- The James Hutton Institute, Invergowrie DD2 5DA, United Kingdom
| | - Alden C Perkins
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Ishan B Ajmera
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Jagdeep Singh Sidhu
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Sacha J Mooney
- Division of Agricultural and Environment Sciences, School of Biosciences, University of Nottingham, Leicestershire LE12 5RD, United Kingdom
- Centre for Plant Integrative Biology, University of Nottingham, Leicestershire LE12 5RD, United Kingdom
| | - Kathleen M Brown
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802
| | - Jonathan P Lynch
- Department of Plant Science, Pennsylvania State University, University Park, PA 16802;
- Division of Agricultural and Environment Sciences, School of Biosciences, University of Nottingham, Leicestershire LE12 5RD, United Kingdom
- Centre for Plant Integrative Biology, University of Nottingham, Leicestershire LE12 5RD, United Kingdom
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Melino VJ, Plett DC, Bendre P, Thomsen HC, Zeisler-Diehl VV, Schreiber L, Kronzucker HJ. Nitrogen depletion enhances endodermal suberization without restricting transporter-mediated root NO 3- influx. JOURNAL OF PLANT PHYSIOLOGY 2021; 257:153334. [PMID: 33373827 DOI: 10.1016/j.jplph.2020.153334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/21/2020] [Accepted: 11/21/2020] [Indexed: 06/12/2023]
Abstract
Roots vary their permeability to aid radial transport of solutes towards xylem vessels in response to nutritional cues. Nitrogen (N) depletion was previously shown to induce early suberization of endodermal cell walls and reduce hydraulic conductivity of barley roots suggesting reduced apoplastic transport of ions (Armand et al., 2019). Suberization may also limit transcellular ion movement by blocking access to transporters (Barberon et al., 2016). The aim of this study was to confirm that N depletion induced suberization in the roots of barley and demonstrate that this was a specific effect in response to NO3- depletion. Furthermore, in roots with early and enhanced suberization, we assessed their ability for transporter-mediated NO3- influx. N depletion induced lateral root elongation and early and enhanced endodermal suberization of the seminal root of each genotype. Both root to shoot NO3- translocation and net N uptake was half that of plants supplied with steady-state NO3-. Genes with predicted functions in suberin synthesis (HvHORST) and NO3- transport (HvNRT2.2) were induced under N-deplete conditions. N-deplete roots had a higher capacity for high-affinity NO3- influx in early suberized roots than under optimal NO3-. In conclusion, NO3- depletion induced early and enhanced suberization in the roots of barley, however, suberization did not restrict transcellular NO3- transport.
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Affiliation(s)
- V J Melino
- School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia; Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
| | - D C Plett
- School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia; School of Agriculture, Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia.
| | - P Bendre
- School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - H C Thomsen
- School of Agriculture, Food and Wine, The University of Adelaide, Urrbrae, SA, 5064, Australia; Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799, Copenhagen V, Denmark.
| | - V V Zeisler-Diehl
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, 53115, Bonn, Germany.
| | - L Schreiber
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, 53115, Bonn, Germany.
| | - H J Kronzucker
- School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, 3010, Australia; Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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25
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Yamauchi T, Noshita K, Tsutsumi N. Climate-smart crops: key root anatomical traits that confer flooding tolerance. BREEDING SCIENCE 2021; 71:51-61. [PMID: 33762876 PMCID: PMC7973492 DOI: 10.1270/jsbbs.20119] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/14/2020] [Indexed: 05/05/2023]
Abstract
Plants require water, but a deficit or excess of water can negatively impact their growth and functioning. Soil flooding, in which root-zone is filled with excess water, restricts oxygen diffusion into the soil. Global climate change is increasing the risk of crop yield loss caused by flooding, and the development of flooding tolerant crops is urgently needed. Root anatomical traits are essential for plants to adapt to drought and flooding, as they determine the balance between the rates of water and oxygen transport. The stele contains xylem and the cortex contains aerenchyma (gas spaces), which respectively contribute to water uptake from the soil and oxygen supply to the roots; this implies that there is a trade-off between the ratio of cortex and stele sizes with respect to adaptation to drought or flooding. In this review, we analyze recent advances in the understanding of root anatomical traits that confer drought and/or flooding tolerance to plants and illustrate the trade-off between cortex and stele sizes. Moreover, we introduce the progress that has been made in modelling and fully automated analyses of root anatomical traits and discuss how key root anatomical traits can be used to improve crop tolerance to soil flooding.
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Affiliation(s)
- Takaki Yamauchi
- Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
| | - Koji Noshita
- Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
- Department of Biology, Kyushu University, Fukuoka, Fukuoka 819–0395, Japan
- Plant Frontier Research Center, Kyushu University, Fukuoka, Fukuoka 819–0395, Japan
| | - Nobuhiro Tsutsumi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
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26
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Niinemets Ü, Ostonen I. Plant organ senescence above- and belowground in trees: how to best salvage resources for new growth? TREE PHYSIOLOGY 2020; 40:981-986. [PMID: 32353147 DOI: 10.1093/treephys/tpaa060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/21/2020] [Indexed: 05/26/2023]
Affiliation(s)
- Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia
- Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia
| | - Ivika Ostonen
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
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27
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Strock CF, Lynch JP. Root secondary growth: an unexplored component of soil resource acquisition. ANNALS OF BOTANY 2020; 126:205-218. [PMID: 32588876 PMCID: PMC7523590 DOI: 10.1093/aob/mcaa068] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND AIMS Despite recent progress in elucidating the molecular basis of secondary growth (cambial growth), the functional implications of this developmental process remain poorly understood. Targeted studies exploring how abiotic and biotic factors affect this process, as well as the relevance of secondary growth to fitness of annual dicotyledonous crop species under stress, are almost entirely absent from the literature. Specifically, the physiological role of secondary growth in roots has been completely neglected yet entails a unique array of implications for plant performance that are distinct from secondary growth in shoot tissue. SCOPE Since roots are directly responsible for soil resource capture, understanding of the fitness landscape of root phenotypes is important in both basic and applied plant biology. Interactions between root secondary growth, edaphic conditions and soil resource acquisition may have significant effects on plant fitness. Our intention here is not to provide a comprehensive review of a sparse and disparate literature, but rather to highlight knowledge gaps, propose hypotheses and identify opportunities for novel and agriculturally relevant research pertaining to secondary growth of roots. This viewpoint: (1) summarizes evidence from our own studies and other published work; (2) proposes hypotheses regarding the fitness landscape of secondary growth of roots in annual dicotyledonous species for abiotic and biotic stress; and (3) highlights the importance of directing research efforts to this topic within an agricultural context. CONCLUSIONS Secondary growth of the roots of annual dicots has functional significance with regards to soil resource acquisition and transport, interactions with soil organisms and carbon sequestration. Research on these topics would contribute significantly toward understanding the agronomic value of secondary growth of roots for crop improvement.
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Affiliation(s)
- Christopher F Strock
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
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28
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Schneider HM, Lynch JP. Should Root Plasticity Be a Crop Breeding Target? FRONTIERS IN PLANT SCIENCE 2020; 11:546. [PMID: 32499798 PMCID: PMC7243933 DOI: 10.3389/fpls.2020.00546] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/09/2020] [Indexed: 05/18/2023]
Abstract
Root phenotypic plasticity has been proposed as a target for the development of more productive crops in variable environments. However, the plasticity of root anatomical and architectural responses to environmental cues is highly complex, and the consequences of these responses for plant fitness are poorly understood. We propose that root phenotypic plasticity may be beneficial in natural or low-input systems in which the availability of soil resources is spatiotemporally dynamic. Crop ancestors and landraces were selected with multiple stresses, competition, significant root loss and heterogenous resource distribution which favored plasticity in response to resource availability. However, in high-input agroecosystems, the value of phenotypic plasticity is unclear, since human management has removed many of these constraints to root function. Further research is needed to understand the fitness landscape of plastic responses including understanding the value of plasticity in different environments, environmental signals that induce plastic responses, and the genetic architecture of plasticity before it is widely adopted in breeding programs. Phenotypic plasticity has many potential ecological, and physiological benefits, but its costs and adaptive value in high-input agricultural systems is poorly understood and merits further research.
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Affiliation(s)
| | - Jonathan P. Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
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29
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Schneider HM, Postma JA, Kochs J, Pflugfelder D, Lynch JP, van Dusschoten D. Spatio-Temporal Variation in Water Uptake in Seminal and Nodal Root Systems of Barley Plants Grown in Soil. FRONTIERS IN PLANT SCIENCE 2020; 11:1247. [PMID: 32903494 PMCID: PMC7438553 DOI: 10.3389/fpls.2020.01247] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/29/2020] [Indexed: 05/11/2023]
Abstract
The spatial and temporal dynamics of root water uptake in nodal and seminal roots are poorly understood, especially in relation to root system development and aging. Here we non-destructively quantify 1) root water uptake and 2) root length of nodal and seminal roots of barley in three dimensions during 43 days of growth. We developed a concentric split root system to hydraulically and physically isolate the seminal and nodal root systems. Using magnetic resonance imaging (MRI), roots were visualized, root length was determined, and soil water depletion in both compartments was measured. From 19 days after germination and onwards, the nodal root system had greater water uptake compared to the seminal root system due to both greater root length and greater root conductivity. At 29 days after germination onwards, the average age of the seminal and nodal root systems was similar and no differences were observed in water uptake per root length between seminal and nodal root systems, indicating the importance of embryonic root systems for seedling establishment and nodal root systems in more mature plants. Since nodal roots perform the majority of water uptake at 29 days after germination and onwards, nodal root phenes merit consideration as a selection target to improve water capture in barley and possibly other crops.
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Affiliation(s)
- Hannah M. Schneider
- Forschungszentrum Jülich, IBG-2, Jülich, Germany
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
| | | | | | | | - Jonathan P. Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, United States
| | - Dagmar van Dusschoten
- Forschungszentrum Jülich, IBG-2, Jülich, Germany
- *Correspondence: Dagmar van Dusschoten,
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30
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Yang JT, Schneider HM, Brown KM, Lynch JP. Genotypic variation and nitrogen stress effects on root anatomy in maize are node specific. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5311-5325. [PMID: 31231768 PMCID: PMC6793441 DOI: 10.1093/jxb/erz293] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 06/11/2019] [Indexed: 05/18/2023]
Abstract
Root phenotypes that improve nitrogen acquisition are avenues for crop improvement. Root anatomy affects resource capture, metabolic cost, hydraulic conductance, anchorage, and soil penetration. Cereal root phenotyping has centered on primary, seminal, and early nodal roots, yet critical nitrogen uptake occurs when the nodal root system is well developed. This study examined root anatomy across nodes in field-grown maize (Zea mays L.) hybrid and inbred lines under high and low nitrogen regimes. Genotypes with high nitrogen use efficiency (NUE) had larger root diameter and less cortical aerenchyma across nodes under stress than genotypes with lower NUE. Anatomical phenes displayed slightly hyperallometric relationships to shoot biomass. Anatomical plasticity varied across genotypes; most genotypes decreased root diameter under stress when averaged across nodes. Cortex, stele, total metaxylem vessel areas, and cortical cell file and metaxylem vessel numbers scaled strongly with root diameter across nodes. Within nodes, metaxylem vessel size and cortical cell size were correlated, and root anatomical phenotypes in the first and second nodes were not representative of subsequent nodes. Node, genotype, and nitrogen treatment affect root anatomy. Understanding nodal variation in root phenes will enable the development of plants that are adapted to low nitrogen conditions.
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Affiliation(s)
- Jennifer T Yang
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
- Present address: Wellesley College, Wellesley, MA 02481, USA
| | - Hannah M Schneider
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Kathleen M Brown
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
- Correspondence:
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31
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Yamauchi T, Tanaka A, Inahashi H, Nishizawa NK, Tsutsumi N, Inukai Y, Nakazono M. Fine control of aerenchyma and lateral root development through AUX/IAA- and ARF-dependent auxin signaling. Proc Natl Acad Sci U S A 2019; 116:20770-20775. [PMID: 31548376 PMCID: PMC6789968 DOI: 10.1073/pnas.1907181116] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Lateral roots (LRs) are derived from a parental root and contribute to water and nutrient uptake from the soil. Auxin/indole-3-acetic acid protein (AUX/IAA; IAA) and auxin response factor (ARF)-mediated signaling are essential for LR formation. Lysigenous aerenchyma, a gas space created by cortical cell death, aids internal oxygen transport within plants. Rice (Oryza sativa) forms lysigenous aerenchyma constitutively under aerobic conditions and increases its formation under oxygen-deficient conditions; however, the molecular mechanisms regulating constitutive aerenchyma (CA) formation remain unclear. LR number is reduced by the dominant-negative effect of a mutated AUX/IAA protein in the iaa13 mutant. We found that CA formation is also reduced in iaa13 We have identified ARF19 as an interactor of IAA13 and identified a lateral organ boundary domain (LBD)-containing protein (LBD1-8) as a target of ARF19. IAA13, ARF19, and LBD1-8 were highly expressed in the cortex and LR primordia, suggesting that these genes function in the initiation of CA and LR formation. Restoration of LBD1-8 expression recovered aerenchyma formation and partly recovered LR formation in the iaa13 background, in which LBD1-8 expression was reduced. An auxin transport inhibitor suppressed CA and LR formation, and a natural auxin stimulated CA formation in the presence of the auxin transport inhibitor. Our findings suggest that CA and LR formation are both regulated through AUX/IAA- and ARF-dependent auxin signaling. The initiation of CA formation lagged that of LR formation, which indicates that the formation of CA and LR are regulated differently by auxin signaling during root development in rice.
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Affiliation(s)
- Takaki Yamauchi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Aichi, Japan;
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, 332-0012 Saitama, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, 113-8657 Tokyo, Japan
| | - Akihiro Tanaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Aichi, Japan
| | - Hiroki Inahashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Aichi, Japan
| | - Naoko K Nishizawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, 113-8657 Tokyo, Japan
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, 921-8836 Ishikawa, Japan
| | - Nobuhiro Tsutsumi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, 113-8657 Tokyo, Japan
| | - Yoshiaki Inukai
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, 332-0012 Saitama, Japan
- International Center for Research and Education in Agriculture, Nagoya University, Nagoya, 464-8601 Aichi, Japan
| | - Mikio Nakazono
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Aichi, Japan;
- The UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Crawley, WA 6009, Australia
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De Bauw P, Vandamme E, Lupembe A, Mwakasege L, Senthilkumar K, Dramé KN, Merckx R. Anatomical root responses of rice to combined phosphorus and water stress - relations to tolerance and breeding opportunities. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:1009-1022. [PMID: 31543094 DOI: 10.1071/fp19002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/20/2019] [Indexed: 06/10/2023]
Abstract
Drought and low P availability are major limitations for rainfed rice (Oryza spp.) production. Root anatomy plays a key role in resource acquisition and tolerance to P and water limitations. Root anatomical responses of three contrasting rice varieties to combinations of different levels of P (deficient to non-limiting) and water availability (water stress to submergence) were evaluated in two pot trials. P availability was the dominant growth-limiting factor, but anatomical root responses to water availability were more prominent than responses to P availability. Cortical cell file number and number of xylem vessels decreased as a response to water stress, but stele and xylem diameter increased. Low P availability induced thinner xylem vessels and a thinner stele. Drought tolerance related to an overall thicker root stele, thicker xylem vessels and a larger water conductance. Some root traits were observed to be more responsive to water and P availability, whereas other traits were more robust to these environmental factors but highly determined by variety. The observed genotypic variation in root anatomy provides opportunities for trait-based breeding. The plasticity of several traits to multiple environmental factors highlights the need for strategic trait selection or breeding adapted to specific target environments.
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Affiliation(s)
- Pieterjan De Bauw
- Katholieke Universiteit Leuven, Dept. of Earth and Environmental Sciences, 3000 Leuven, Belgium; and Corresponding author.
| | - Elke Vandamme
- International Potato Center (CIP), PO Box 1269, Kigali, Rwanda; and Africa Rice Center (AfricaRice), PO Box 33581, Dar es Salaam, Tanzania
| | - Allen Lupembe
- Africa Rice Center (AfricaRice), PO Box 33581, Dar es Salaam, Tanzania
| | - Leah Mwakasege
- Africa Rice Center (AfricaRice), PO Box 33581, Dar es Salaam, Tanzania
| | - Kalimuthu Senthilkumar
- Africa Rice Center (AfricaRice), PO Box 33581, Dar es Salaam, Tanzania; and Africa Rice Center (AfricaRice), PO Box 1690, Antananarivo, Madagascar
| | - Khady N Dramé
- Africa Rice Center (AfricaRice), 01 BP 4029, Abidjan, Côte d'Ivoire
| | - Roel Merckx
- Katholieke Universiteit Leuven, Dept. of Earth and Environmental Sciences, 3000 Leuven, Belgium
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Mohammed U, Caine RS, Atkinson JA, Harrison EL, Wells D, Chater CC, Gray JE, Swarup R, Murchie EH. Rice plants overexpressing OsEPF1 show reduced stomatal density and increased root cortical aerenchyma formation. Sci Rep 2019; 9:5584. [PMID: 30944383 PMCID: PMC6447545 DOI: 10.1038/s41598-019-41922-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 03/19/2019] [Indexed: 01/07/2023] Open
Abstract
Stomata are adjustable pores in the aerial epidermis of plants. The role of stomata is usually described in terms of the trade-off between CO2 uptake and water loss. Little consideration has been given to their interaction with below-ground development or diffusion of other gases. We overexpressed the rice EPIDERMAL PATTERNING FACTOR1 (OsEPF1) to produce rice plants with reduced stomatal densities, resulting in lowered leaf stomatal conductance and enhanced water use efficiency. Surprisingly, we found that root cortical aerenchyma (RCA) is formed constitutively in OsEPF1OE lines regardless of tissue age and position. Aerenchyma is tissue containing air-spaces that can develop in the plant root during stressful conditions, e.g. oxygen deficiency when it functions to increase O2 diffusion from shoot to root. The relationship with stomata is unknown. We conclude that RCA development and stomatal development are linked by two possible mechanisms: first that reduced stomatal conductance inhibits the diffusion of oxygen to the root, creating an oxygen deficit and stimulating the formation of RCA, second that an unknown EPF signalling pathway may be involved. Our observations have fundamental implications for the understanding of whole plant gas diffusion and root-to-shoot signalling events.
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Affiliation(s)
- U. Mohammed
- 0000 0004 1936 8868grid.4563.4Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington campus, LE12 5RD Nottingham, UK
| | - R. S. Caine
- 0000 0004 1936 9262grid.11835.3eDepartment of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, S10 2TN Sheffield, UK
| | - J. A. Atkinson
- 0000 0004 1936 8868grid.4563.4Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington campus, LE12 5RD Nottingham, UK
| | - E. L. Harrison
- 0000 0004 1936 9262grid.11835.3eDepartment of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, S10 2TN Sheffield, UK
| | - D. Wells
- 0000 0004 1936 8868grid.4563.4Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington campus, LE12 5RD Nottingham, UK
| | - C. C. Chater
- 0000 0004 1936 9262grid.11835.3eDepartment of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, S10 2TN Sheffield, UK
| | - J. E. Gray
- 0000 0004 1936 9262grid.11835.3eDepartment of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, S10 2TN Sheffield, UK
| | - R. Swarup
- 0000 0004 1936 8868grid.4563.4Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington campus, LE12 5RD Nottingham, UK
| | - E. H. Murchie
- 0000 0004 1936 8868grid.4563.4Division of Plant and Crop Science, School of Biosciences, University of Nottingham, Sutton Bonington campus, LE12 5RD Nottingham, UK
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York LM. Functional phenomics: an emerging field integrating high-throughput phenotyping, physiology, and bioinformatics. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:379-386. [PMID: 30380107 DOI: 10.1093/jxb/ery379] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 10/22/2018] [Indexed: 05/03/2023]
Abstract
The emergence of functional phenomics signifies the rebirth of physiology as a 21st century science through the use of advanced sensing technologies and big data analytics. Functional phenomics seeks to fill the significant knowledge gaps that still exist in the relationship of plant phenotype to function. Here, a general approach for the theory and practice of functional phenomics is outlined. The functional phenomics pipeline is proposed as a general method for conceptualizing, measuring, and validating utility of plant phenes, or elemental units of phenotype. The functional phenomics pipeline begins with ideotype development. Second, a phenotyping platform is developed to maximize the throughput of phene measurements. Target phenes and indicators of plant function, or performance, are measured in a mapping population. Forward genetics allows genetic mapping, while functional phenomics links phenes to plant performance. Based on these data, genotypes with contrasting phenotypes can be selected for smaller yet more intensive experiments to understand phene-environment interactions in depth. Simulation modeling is used to further understand the phenotypes, and all stages of the pipeline feed back to ideotype and phenotyping platform development. In total, functional phenomics represents an evolution of pre-existing disciplines, but the goals and unique methodologies constitute a novel research program.
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Jia X, Liu P, Lynch JP. Greater lateral root branching density in maize improves phosphorus acquisition from low phosphorus soil. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4961-4970. [PMID: 30295904 PMCID: PMC6137997 DOI: 10.1093/jxb/ery252] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 07/03/2018] [Indexed: 05/03/2023]
Abstract
The development of crops with better growth under suboptimal phosphorus availability would improve food security in developing countries while reducing environmental pollution in developed countries. We tested the hypothesis that maize (Zea mays) phenotypes with greater lateral root branching density have greater phosphorus acquisition from low phosphorus soils. Recombinant inbred lines with either 'many short' (MS) or 'few long' (FL) lateral root phenotypes were grown under high and low phosphorus conditions in greenhouse mesocosms and in the field. Under low phosphorus in mesocosms, lines with the MS phenotype had 89% greater phosphorus acquisition and 48% more shoot biomass than FL lines. Under low phosphorus in the field, MS lines had 16% shallower rooting depth (D95), 81% greater root length density in the top 20 cm of the soil, 49% greater shoot phosphorus content, 12% greater leaf photosynthesis, 19% greater shoot biomass, and 14% greater grain yield than FL lines. These results are consistent with the hypothesis that the phenotype of many, shorter lateral roots improves phosphorus acquisition under low phosphorus availability and merits consideration for genetic improvement of phosphorus efficiency in maize and other crops.
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Affiliation(s)
- Xucun Jia
- College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an, Shandong Province, China
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Peng Liu
- College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an, Shandong Province, China
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
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Sundgren TK, Uhlen AK, Lillemo M, Briese C, Wojciechowski T. Rapid seedling establishment and a narrow root stele promotes waterlogging tolerance in spring wheat. JOURNAL OF PLANT PHYSIOLOGY 2018; 227:45-55. [PMID: 29735176 DOI: 10.1016/j.jplph.2018.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/10/2018] [Accepted: 04/16/2018] [Indexed: 05/11/2023]
Abstract
Improving the waterlogging tolerance of wheat varieties could alleviate yield constraints caused by excessive rain and poor soil drainage. In this study, we investigated root and shoot growth as well as anatomical traits of six spring wheat genotypes with contrasting waterlogging tolerance properties. Our aim was to identify root traits that differentiate tolerant from sensitive genotypes. Two experiments were conducted using rhizoboxes and photography for data acquisition. In experiment one, root growth of the genotypes was studied during seedling establishment and a subsequent waterlogging treatment, starting at the 3-leaf stage and maintained for seven days. In the second experiment, root and shoot growth of previously waterlogged plants was compared between the genotypes during seven days of recovery. At harvest of experiment two, root segments were sampled to investigate genotype differences of root cross sectional area, root cortex area, stele area and percentage of aerenchyma. The results show that tolerant, in contrast to sensitive genotypes, developed seminal roots faster in the seedling establishment phase and more nodal roots during the waterlogging treatment. NK93602 and Bjarne were the best performing genotypes. Bjarne in particular had a narrower relative stele size of nodal (13.4%) and seminal roots (11.7%) compared to other genotypes (e.g. 16.3% in nodal roots and 13.9% in seminal roots of sensitive Quarna). The results from this study suggests that early vigor is an important trait for waterlogging tolerance in the field. Anatomical root traits, such as a narrow stele and aerenchyma may contribute to improving waterlogging tolerance furthermore.
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Affiliation(s)
- Tove Kristina Sundgren
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway.
| | - Anne Kjersti Uhlen
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Lillemo
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Christoph Briese
- IBG-2 (Plant Sciences), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich, Germany
| | - Tobias Wojciechowski
- IBG-2 (Plant Sciences), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich, Germany
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Schneider HM, Wojciechowski T, Postma JA, Brown KM, Lynch JP. Ethylene modulates root cortical senescence in barley. ANNALS OF BOTANY 2018; 122:95-105. [PMID: 29897390 PMCID: PMC6025243 DOI: 10.1093/aob/mcy059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/05/2018] [Indexed: 05/08/2023]
Abstract
Background and Aims Root cortical senescence (RCS) is a poorly understood phenomenon with implications for adaptation to edaphic stress. It was hypothesized that RCS in barley (Hordeum vulgare L.) is (1) accelerated by exogenous ethylene exposure; (2) accompanied by differential expression of ethylene synthesis and signalling genes; and (3) associated with differential expression of programmed cell death (PCD) genes. Methods Gene expression of root segments from four barley genotypes with and without RCS was evaluated using quantitative real-time PCR (qRT-PCR). The progression of RCS was manipulated with root zone ethylene and ethylene inhibitor applications. Key Results The results demonstrate that ethylene modulates RCS. Four genes related to ethylene synthesis and signalling were upregulated during RCS in optimal, low nitrogen and low phosphorus nutrient regimes. RCS was accelerated by root zone ethylene treatment, and this effect was reversed by an ethylene action inhibitor. Roots treated with exogenous ethylene had 35 and 46 % more cortical senescence compared with the control aeration treatment in seminal and nodal roots, respectively. RCS was correlated with expression of two genes related to programmed cell death (PCD). Conclusions The development of RCS is similar to root cortical aerenchyma formation with respect to ethylene modulation of the PCD process.
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Affiliation(s)
- Hannah M Schneider
- Forschungszentrum Jülich, Institut für Bio- und Geowissenschaften Pflanzenwissenschaften (IBG-2), Jülich, Germany
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Tobias Wojciechowski
- Forschungszentrum Jülich, Institut für Bio- und Geowissenschaften Pflanzenwissenschaften (IBG-2), Jülich, Germany
| | - Johannes A Postma
- Forschungszentrum Jülich, Institut für Bio- und Geowissenschaften Pflanzenwissenschaften (IBG-2), Jülich, Germany
| | - Kathleen M Brown
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
| | - Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
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Lynch JP. Rightsizing root phenotypes for drought resistance. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3279-3292. [PMID: 29471525 DOI: 10.1093/jxb/ery048] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 01/30/2018] [Indexed: 05/06/2023]
Abstract
I propose that reduced root development would be advantageous for drought resistance in high-input agroecosystems. Selection regimes for crop ancestors and landraces include multiple stresses, intense competition, and variable resource distribution, which favored prolific root production, developmental plasticity in response to resource availability, and maintenance of unspecialized root tissues. High-input agroecosystems have removed many of these constraints to root function. Therefore, root phenotypes that focus on water capture at the expense of ancestral adaptations would be better suited to high-input agroecosystems. Parsimonious architectural phenotypes include fewer axial roots, reduced density of lateral roots, reduced growth responsiveness to local resource availability, and greater loss of roots that do not contribute to water capture. Parsimonious anatomical phenotypes include a reduced number of cortical cell files, greater loss of cortical parenchyma to aerenchyma and senescence, and larger cortical cell size. Parsimonious root phenotypes may be less useful in low-input agroecosystems, which are characterized by multiple challenges and trade-offs for root function in addition to water capture. Analysis of the fitness landscape of root phenotypes is a complex challenge that will be aided by the development of robust functional-structural models capable of simulating the dynamics of root-soil interactions.
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Affiliation(s)
- Jonathan P Lynch
- Department of Plant Science, The Pennsylvania State University, University Park, PA, USA
- School of Biosciences, University of Nottingham, Sutton Bonington, Leicestershire, UK
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Shi R, Melzer M, Zheng S, Benke A, Stich B, von Wirén N. Iron Retention in Root Hemicelluloses Causes Genotypic Variability in the Tolerance to Iron Deficiency-Induced Chlorosis in Maize. FRONTIERS IN PLANT SCIENCE 2018; 9:557. [PMID: 29755495 PMCID: PMC5932200 DOI: 10.3389/fpls.2018.00557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 04/09/2018] [Indexed: 05/25/2023]
Abstract
Antagonistic interactions of phosphorus (P) hamper iron (Fe) acquisition by plants and can cause Fe deficiency-induced chlorosis. To determine the physiological processes underlying adverse Fe-P interactions, the maize lines B73 and Mo17, which differ in chlorosis susceptibility, were grown hydroponically at different Fe:P ratios. In the presence of P, Mo17 became more chlorotic than B73. The higher sensitivity of Mo17 to Fe deficiency was not related to Fe-P interactions in leaves but to lower Fe translocation to shoots, which coincided with a larger pool of Fe being fixed in the root apoplast of P-supplied Mo17 plants. Fractionating cell wall components from roots showed that most of the cell wall-contained P accumulated in pectin, whereas most of the Fe was bound to root hemicelluloses, revealing that co-precipitation of Fe and P in the apoplast was not responsible for Fe inactivation in roots. A negative correlation between chlorophyll index and hemicellulose-bound Fe in 85 inbred lines of the intermated maize B73 × Mo17 (IBM) population indicated that apoplastic Fe retention contributes to genotypic differences in chlorosis susceptibility of maize grown under low Fe supplies. Our study indicates that Fe retention in the hemicellulose fraction of roots is an important determinant in the tolerance to Fe deficiency-induced chlorosis of graminaceous plant species with low phytosiderophore release, like maize.
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Affiliation(s)
- Rongli Shi
- Department of Physiology and Cell Biology, Leibniz-Institute for Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Michael Melzer
- Department of Physiology and Cell Biology, Leibniz-Institute for Plant Genetics and Crop Plant Research, Gatersleben, Germany
| | - Shaojian Zheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Andreas Benke
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Benjamin Stich
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Nicolaus von Wirén
- Department of Physiology and Cell Biology, Leibniz-Institute for Plant Genetics and Crop Plant Research, Gatersleben, Germany
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Végh A, Incze N, Fábián A, Huo H, Bradford KJ, Balázs E, Soós V. Comprehensive Analysis of DWARF14-LIKE2 (DLK2) Reveals Its Functional Divergence from Strigolactone-Related Paralogs. FRONTIERS IN PLANT SCIENCE 2017; 8:1641. [PMID: 28970845 PMCID: PMC5609103 DOI: 10.3389/fpls.2017.01641] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/06/2017] [Indexed: 05/20/2023]
Abstract
Strigolactones (SLs) and related butenolides, originally identified as active seed germination stimulants of parasitic weeds, play important roles in many aspects of plant development. Two members of the D14 α/β hydrolase protein family, DWARF14 (D14) and KARRIKIN INSENSITIVE2 (KAI2) are essential for SL/butenolide signaling. The third member of the family in Arabidopsis, DWARF 14-LIKE2 (DLK2) is structurally very similar to D14 and KAI2, but its function is unknown. We demonstrated that DLK2 does not bind nor hydrolyze natural (+)5-deoxystrigol [(+)5DS], and weakly hydrolyzes non-natural strigolactone (-)5DS. A detailed genetic analysis revealed that DLK2 does not affect SL responses and can regulate seedling photomorphogenesis. DLK2 is upregulated in the dark dependent upon KAI2 and PHYTOCHROME INTERACTING FACTORS (PIFs), indicating that DLK2 might function in light signaling pathways. In addition, unlike its paralog proteins, DLK2 is not subject to rac-GR24-induced degradation, suggesting that DLK2 acts independently of MORE AXILLARY GROWTH2 (MAX2); however, regulation of DLK2 transcription is mostly accomplished through MAX2. In conclusion, these data suggest that DLK2 represents a divergent member of the DWARF14 family.
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Affiliation(s)
- Attila Végh
- Department of Applied Genomics, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary
| | - Norbert Incze
- Department of Applied Genomics, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary
| | - Attila Fábián
- Department of Plant Cell Biology, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary
| | - Heqiang Huo
- Department of Plant Sciences, Seed Biotechnology Center, University of California, Davis, DavisCA, United States
| | - Kent J. Bradford
- Department of Plant Sciences, Seed Biotechnology Center, University of California, Davis, DavisCA, United States
| | - Ervin Balázs
- Department of Applied Genomics, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary
| | - Vilmos Soós
- Department of Applied Genomics, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of SciencesMartonvasar, Hungary
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