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Henry A, Swamy BPM, Dixit S, Torres RD, Batoto TC, Manalili M, Anantha MS, Mandal NP, Kumar A. Physiological mechanisms contributing to the QTL-combination effects on improved performance of IR64 rice NILs under drought. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1787-99. [PMID: 25680791 PMCID: PMC4378621 DOI: 10.1093/jxb/eru506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 11/26/2014] [Accepted: 12/01/2014] [Indexed: 05/04/2023]
Abstract
Characterizing the physiological mechanisms behind major-effect drought-yield quantitative trait loci (QTLs) can provide an understanding of the function of the QTLs-as well as plant responses to drought in general. In this study, we characterized rice (Oryza sativa L.) genotypes with QTLs derived from drought-tolerant traditional variety AdaySel that were introgressed into drought-susceptible high-yielding variety IR64, one of the most popular megavarieties in South Asian rainfed lowland systems. Of the different combinations of the four QTLs evaluated, genotypes with two QTLs (qDTY 2.2 + qDTY 4.1 ) showed the greatest degree of improvement under drought compared with IR64 in terms of yield, canopy temperature, and normalized difference vegetation index (NDVI). Furthermore, qDTY 2.2 and qDTY 4.1 showed a potential for complementarity in that they were each most effective under different severities of drought stress. Multiple drought-response mechanisms were observed to be conferred in the genotypes with the two-QTL combination: higher root hydraulic conductivity and in some cases greater root growth at depth. As evidenced by multiple leaf water status and plant growth indicators, these traits affected transpiration but not transpiration efficiency or harvest index. The results from this study highlight the complex interactions among major-effect drought-yield QTLs and the drought-response traits they confer, and the need to evaluate the optimal combinations of QTLs that complement each other when present in a common genetic background.
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Affiliation(s)
- Amelia Henry
- International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | | | - Shalabh Dixit
- International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - Rolando D Torres
- International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - Tristram C Batoto
- International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - Mervin Manalili
- International Rice Research Institute, Los Baños, Laguna 4031, Philippines
| | - M S Anantha
- Central Rainfed Upland Rice Research Station, Hazaribag, Jharkand 825 301, India
| | - N P Mandal
- Central Rainfed Upland Rice Research Station, Hazaribag, Jharkand 825 301, India
| | - Arvind Kumar
- Central Rainfed Upland Rice Research Station, Hazaribag, Jharkand 825 301, India
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102
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Robbins NE, Dinneny JR. The divining root: moisture-driven responses of roots at the micro- and macro-scale. JOURNAL OF EXPERIMENTAL BOTANY 2015. [PMID: 25617469 DOI: 10.1093/jxb/eru49496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Water is fundamental to plant life, but the mechanisms by which plant roots sense and respond to variations in water availability in the soil are poorly understood. Many studies of responses to water deficit have focused on large-scale effects of this stress, but have overlooked responses at the sub-organ or cellular level that give rise to emergent whole-plant phenotypes. We have recently discovered hydropatterning, an adaptive environmental response in which roots position new lateral branches according to the spatial distribution of available water across the circumferential axis. This discovery illustrates that roots are capable of sensing and responding to water availability at spatial scales far lower than those normally studied for such processes. This review will explore how roots respond to water availability with an emphasis on what is currently known at different spatial scales. Beginning at the micro-scale, there is a discussion of water physiology at the cellular level and proposed sensory mechanisms cells use to detect osmotic status. The implications of these principles are then explored in the context of cell and organ growth under non-stress and water-deficit conditions. Following this, several adaptive responses employed by roots to tailor their functionality to the local moisture environment are discussed, including patterning of lateral root development and generation of hydraulic barriers to limit water loss. We speculate that these micro-scale responses are necessary for optimal functionality of the root system in a heterogeneous moisture environment, allowing for efficient water uptake with minimal water loss during periods of drought.
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Affiliation(s)
- Neil E Robbins
- Carnegie Institution for Science, Department of Plant Biology, 260 Panama Street, Stanford, CA 94305, USA Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA 94305, USA
| | - José R Dinneny
- Carnegie Institution for Science, Department of Plant Biology, 260 Panama Street, Stanford, CA 94305, USA
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103
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Lima JM, Nath M, Dokku P, Raman KV, Kulkarni KP, Vishwakarma C, Sahoo SP, Mohapatra UB, Mithra SVA, Chinnusamy V, Robin S, Sarla N, Seshashayee M, Singh K, Singh AK, Singh NK, Sharma RP, Mohapatra T. Physiological, anatomical and transcriptional alterations in a rice mutant leading to enhanced water stress tolerance. AOB PLANTS 2015; 7:plv023. [PMID: 25818072 PMCID: PMC4482838 DOI: 10.1093/aobpla/plv023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 02/26/2015] [Indexed: 05/04/2023]
Abstract
Water stress is one of the most severe constraints to crop productivity. Plants display a variety of physiological and biochemical responses both at the cellular and whole organism level upon sensing water stress. Leaf rolling, stomatal closure, deeper root penetration, higher relative water content (RWC) and better osmotic adjustment are some of the mechanisms that plants employ to overcome water stress. In the current study, we report a mutant, enhanced water stress tolerant1 (ewst1) with enhanced water stress tolerance, identified from the ethyl methanesulfonate-induced mutant population of rice variety Nagina22 by field screening followed by withdrawal of irrigation in pots and hydroponics (PEG 6000). Though ewst1 was morphologically similar to the wild type (WT) for 35 of the 38 morphological descriptors (except chalky endosperm/expression of white core, decorticated grain colour and grain weight), it showed enhanced germination in polyethylene glycol-infused medium. It exhibited increase in maximum root length without any significant changes in its root weight, root volume and total root number on crown when compared with the WT under stress in PVC tube experiment. It also showed better performance for various physiological parameters such as RWC, cell membrane stability and chlorophyll concentration upon water stress in a pot experiment. Root anatomy and stomatal microscopic studies revealed changes in the number of xylem and phloem cells, size of central meta-xylem and number of closed stomata in ewst1. Comparative genome-wide transcriptome analysis identified genes related to exocytosis, secondary metabolites, tryptophan biosynthesis, protein phosphorylation and other signalling pathways to be playing a role in enhanced response to water stress in ewst1. The possible involvement of a candidate gene with respect to the observed morpho-physiological and transcriptional changes and its role in stress tolerance are discussed. The mutant identified and characterized in this study will be useful for further dissection of water stress tolerance in rice.
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Affiliation(s)
- John Milton Lima
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India Department of Botany, North Orissa University, Baripada, Odisha, India
| | - Manoj Nath
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - Prasad Dokku
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - K V Raman
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - K P Kulkarni
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - C Vishwakarma
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - S P Sahoo
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - U B Mohapatra
- Department of Botany, North Orissa University, Baripada, Odisha, India
| | - S V Amitha Mithra
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - V Chinnusamy
- Indian Agricultural Research Institute, New Delhi, India
| | - S Robin
- Tamil Nadu Agricultural University, Coimbatore, India
| | - N Sarla
- Directorate of Rice Research, Hyderabad, India
| | - M Seshashayee
- University of Agricultural Sciences, Bangalore, India
| | - K Singh
- Punjab Agricultural University, Ludhiana, India
| | - A K Singh
- Indian Agricultural Research Institute, New Delhi, India
| | - N K Singh
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - R P Sharma
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India
| | - T Mohapatra
- National Research Centre on Plant Biotechnology, IARI, New Delhi, India Present address: Central Rice Research Institute, Cuttack, Odisha, India
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104
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Ahmadi N, Audebert A, Bennett MJ, Bishopp A, de Oliveira AC, Courtois B, Diedhiou A, Diévart A, Gantet P, Ghesquière A, Guiderdoni E, Henry A, Inukai Y, Kochian L, Laplaze L, Lucas M, Luu DT, Manneh B, Mo X, Muthurajan R, Périn C, Price A, Robin S, Sentenac H, Sine B, Uga Y, Véry AA, Wissuwa M, Wu P, Xu J. The roots of future rice harvests. RICE (NEW YORK, N.Y.) 2014; 7:29. [PMID: 26224558 PMCID: PMC4884021 DOI: 10.1186/s12284-014-0029-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 10/12/2014] [Indexed: 05/05/2023]
Abstract
Rice production faces the challenge to be enhanced by 50% by year 2030 to meet the growth of the population in rice-eating countries. Whereas yield of cereal crops tend to reach plateaus and a yield is likely to be deeply affected by climate instability and resource scarcity in the coming decades, building rice cultivars harboring root systems that can maintain performance by capturing water and nutrient resources unevenly distributed is a major breeding target. Taking advantage of gathering a community of rice root biologists in a Global Rice Science Partnership workshop held in Montpellier, France, we present here the recent progresses accomplished in this area and focal points where an international network of laboratories should direct their efforts.
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Affiliation(s)
| | | | - Malcolm J Bennett
- />Centre for Plant Integrative Biology, University of Nottingham, Loughborough, LE12 5RD UK
| | - Anthony Bishopp
- />Centre for Plant Integrative Biology, University of Nottingham, Loughborough, LE12 5RD UK
| | | | | | - Abdala Diedhiou
- />Université Cheikh Anta Diop (UCAD), Département de Biologie Végétale, Laboratoire Commun de Microbiologie IRD/ISRA/UCAD, Centre de Recherche de Bel Air - BP 1386, CP 18524 Dakar, Sénégal
- />Laboratoire Mixte International Adaptation des Plantes et microorganismes associés aux Stress Environnementaux (LAPSE), Centre de Recherche de Bel Air - BP 1386, CP 18524 Dakar, Sénégal
| | - Anne Diévart
- />CIRAD, UMR AGAP, Montpellier Cedex 5, 34398 France
| | - Pascal Gantet
- />Université Montpellier 2, UMR DIADE, Montpellier, France
- />IRD, LMI RICE, USTH, Agronomical Genetics Institute, Hanoi, Vietnam
| | | | | | | | - Yoshiaki Inukai
- />International Cooperation Center for Agricultural Education (ICCAE), Nagoya University, Furo-cho, Chikusa 464-8601 Nagoya, Japan
| | - Leon Kochian
- />Robert W. Holley Center for Agriculture and Health, USDA-ARS and Department of Plant Biology, Cornell University, Ithaca, 14853 NY USA
| | - Laurent Laplaze
- />Laboratoire Mixte International Adaptation des Plantes et microorganismes associés aux Stress Environnementaux (LAPSE), Centre de Recherche de Bel Air - BP 1386, CP 18524 Dakar, Sénégal
- />IRD, UMR DIADE, Montpellier, France
| | | | - Doan Trung Luu
- />Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, UMR 5004 CNRS/386 INRA/Montpellier SupAgro/Université Montpellier 2, F-34060 Montpellier Cedex 2, France
| | - Baboucarr Manneh
- />Africa Rice Center, AfricaRice Sahel Regional Station, B.P. 96, St Louis, Senegal
| | - Xiaorong Mo
- />State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou, 310058 China
| | | | | | - Adam Price
- />University of Aberdeen, Aberdeen, AB24 3UU UK
| | | | - Hervé Sentenac
- />Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, UMR 5004 CNRS/386 INRA/Montpellier SupAgro/Université Montpellier 2, F-34060 Montpellier Cedex 2, France
| | - Bassirou Sine
- />Laboratoire Mixte International Adaptation des Plantes et microorganismes associés aux Stress Environnementaux (LAPSE), Centre de Recherche de Bel Air - BP 1386, CP 18524 Dakar, Sénégal
- />ISRA, CERAAS, Thiès, Senegal
| | - Yusaku Uga
- />National Institute of Agrobiological Sciences (NIAS), 2-1-2 Kannondai, Tsukuba, 305-8602 Ibaraki, Japan
| | - Anne Aliénor Véry
- />Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes, UMR 5004 CNRS/386 INRA/Montpellier SupAgro/Université Montpellier 2, F-34060 Montpellier Cedex 2, France
| | - Matthias Wissuwa
- />Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, 305-8686 Japan
| | - Ping Wu
- />State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou, 310058 China
| | - Jian Xu
- />Department of Biological Sciences and NUS Centre for BioImaging Sciences, Faculty of Science, National University of Singapore, Singapore 117543 Singapore
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105
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Meister R, Rajani MS, Ruzicka D, Schachtman DP. Challenges of modifying root traits in crops for agriculture. TRENDS IN PLANT SCIENCE 2014; 19:779-88. [PMID: 25239776 DOI: 10.1016/j.tplants.2014.08.005] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 08/05/2014] [Accepted: 08/21/2014] [Indexed: 05/20/2023]
Abstract
Roots play an essential role in the acquisition of water and minerals from soils. Measuring crop root architecture and assaying for changes in function can be challenging, but examples have emerged showing that modifications to roots result in higher yield and increased stress tolerance. In this review, we focus mainly on the molecular genetic advances that have been made in altering root system architecture and function in crop plants, as well as phenotyping methods. The future for the modification of crop plant roots looks promising based on recent advances, but there are also important challenges ahead.
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Affiliation(s)
- Robert Meister
- Monsanto Company, 700 Chesterfield Parkway, Chesterfield, MO 63017, USA
| | - M S Rajani
- Monsanto Company, 700 Chesterfield Parkway, Chesterfield, MO 63017, USA
| | - Daniel Ruzicka
- Monsanto Company, 700 Chesterfield Parkway, Chesterfield, MO 63017, USA
| | - Daniel P Schachtman
- University of Nebraska Lincoln, Center for Plant Science Innovation, E243 Beadle, Lincoln, NE 68588-0660, USA.
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106
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Lynch JP, Chimungu JG, Brown KM. Root anatomical phenes associated with water acquisition from drying soil: targets for crop improvement. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6155-66. [PMID: 24759880 DOI: 10.1093/jxb/eru162] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Several root anatomical phenes affect water acquisition from drying soil, and may therefore have utility in breeding more drought-tolerant crops. Anatomical phenes that reduce the metabolic cost of the root cortex ('cortical burden') improve soil exploration and therefore water acquisition from drying soil. The best evidence for this is for root cortical aerenchyma; cortical cell file number and cortical senescence may also be useful in this context. Variation in the number and diameter of xylem vessels strongly affects axial water conductance. Reduced axial conductance may be useful in conserving soil water so that a crop may complete its life cycle under terminal drought. Variation in the suberization and lignification of the endodermis and exodermis affects radial water conductance, and may therefore be important in reducing water loss from mature roots into dry soil. Rhizosheaths may protect the water status of young root tissue. Root hairs and larger diameter root tips improve root penetration of hard, drying soil. Many of these phenes show substantial genotypic variation. The utility of these phenes for water acquisition has only rarely been validated, and may have strong interactions with the spatiotemporal dynamics of soil water availability, and with root architecture and other aspects of the root phenotype. This complexity calls for structural-functional plant modelling and 3D imaging methods. Root anatomical phenes represent a promising yet underexplored and untapped source of crop breeding targets.
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Affiliation(s)
- Jonathan P Lynch
- Department of Plant Science, Penn State University, University Park, PA 16802, USA
| | - Joseph G Chimungu
- Department of Plant Science, Penn State University, University Park, PA 16802, USA
| | - Kathleen M Brown
- Department of Plant Science, Penn State University, University Park, PA 16802, USA
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107
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Vadez V, Kholova J, Medina S, Kakkera A, Anderberg H. Transpiration efficiency: new insights into an old story. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6141-53. [PMID: 24600020 DOI: 10.1093/jxb/eru040] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Producing more food per unit of water has never been as important as it is at present, and the demand for water by economic sectors other than agriculture will necessarily put a great deal of pressure on a dwindling resource, leading to a call for increases in the productivity of water in agriculture. This topic has been given high priority in the research agenda for the last 30 years, but with the exception of a few specific cases, such as water-use-efficient wheat in Australia, breeding crops for water-use efficiency has yet to be accomplished. Here, we review the efforts to harness transpiration efficiency (TE); that is, the genetic component of water-use efficiency. As TE is difficult to measure, especially in the field, evaluations of TE have relied mostly on surrogate traits, although this has most likely resulted in over-dependence on the surrogates. A new lysimetric method for assessing TE gravimetrically throughout the entire cropping cycle has revealed high genetic variation in different cereals and legumes. Across species, water regimes, and a wide range of genotypes, this method has clearly established an absence of relationships between TE and total water use, which dismisses previous claims that high TE may lead to a lower production potential. More excitingly, a tight link has been found between these large differences in TE in several crops and attributes of plants that make them restrict water losses under high vapour-pressure deficits. This trait provides new insight into the genetics of TE, especially from the perspective of plant hydraulics, probably with close involvement of aquaporins, and opens new possibilities for achieving genetic gains via breeding focused on this trait. Last but not least, small amounts of water used in specific periods of the crop cycle, such as during grain filling, may be critical. We assessed the efficiency of water use at these critical stages.
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Affiliation(s)
- Vincent Vadez
- International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Crop Physiology Laboratory, Patancheru 502324, Greater Hyderabad, Andhra Pradesh, India
| | - Jana Kholova
- International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Crop Physiology Laboratory, Patancheru 502324, Greater Hyderabad, Andhra Pradesh, India
| | - Susan Medina
- International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Crop Physiology Laboratory, Patancheru 502324, Greater Hyderabad, Andhra Pradesh, India
| | - Aparna Kakkera
- International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Crop Physiology Laboratory, Patancheru 502324, Greater Hyderabad, Andhra Pradesh, India
| | - Hanna Anderberg
- Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, Sweden
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108
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Robbins NE, Trontin C, Duan L, Dinneny JR. Beyond the barrier: communication in the root through the endodermis. PLANT PHYSIOLOGY 2014; 166:551-9. [PMID: 25125504 PMCID: PMC4213087 DOI: 10.1104/pp.114.244871] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The root endodermis is characterized by the Casparian strip and by the suberin lamellae, two hydrophobic barriers that restrict the free diffusion of molecules between the inner cell layers of the root and the outer environment. The presence of these barriers and the position of the endodermis between the inner and outer parts of the root require that communication between these two domains acts through the endodermis. Recent work on hormone signaling, propagation of calcium waves, and plant-fungal symbiosis has provided evidence in support of the hypothesis that the endodermis acts as a signaling center. The endodermis is also a unique mechanical barrier to organogenesis, which must be overcome through chemical and mechanical cross talk between cell layers to allow for development of new lateral organs while maintaining its barrier functions. In this review, we discuss recent findings regarding these two important aspects of the endodermis.
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Affiliation(s)
- Neil E Robbins
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (N.E.R., C.T., L.D., J.R.D.); andDepartment of Biology, Stanford University, Stanford, California 94305 (N.E.R.)
| | - Charlotte Trontin
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (N.E.R., C.T., L.D., J.R.D.); andDepartment of Biology, Stanford University, Stanford, California 94305 (N.E.R.)
| | - Lina Duan
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (N.E.R., C.T., L.D., J.R.D.); andDepartment of Biology, Stanford University, Stanford, California 94305 (N.E.R.)
| | - José R Dinneny
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (N.E.R., C.T., L.D., J.R.D.); andDepartment of Biology, Stanford University, Stanford, California 94305 (N.E.R.)
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109
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Effect of salt stress on seedling growth and antioxidant enzymes in two contrasting rice introgression lines. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s40502-014-0061-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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110
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Schoppach RM, Wauthelet D, Jeanguenin L, Sadok W. Conservative water use under high evaporative demand associated with smaller root metaxylem and limited trans-membrane water transport in wheat. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:257-269. [PMID: 32480986 DOI: 10.1071/fp13211] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/23/2013] [Indexed: 05/24/2023]
Abstract
Efficient breeding of drought-tolerant wheat (Triticum spp.) genotypes requires identifying mechanisms underlying exceptional performances. Evidence indicates that the drought-tolerant breeding line RAC875 is water-use conservative, limiting its transpiration rate (TR) sensitivity to increasing vapour pressure deficit (VPD), thereby saving soil water moisture for later use. However, the physiological basis of the response remains unknown. The involvement of leaf and root developmental, anatomical and hydraulic features in regulating high-VPD, whole-plant TR was investigated on RAC875 and a drought-sensitive cultivar (Kukri) in 12 independent hydroponic and pot experiments. Leaf areas and stomatal densities were found to be identical between lines and de-rooted plants didn't exhibit differential TR responses to VPD or TR sensitivity to four aquaporin (AQP) inhibitors that included mercury chloride (HgCl2). However, intact plants exhibited a differential sensitivity to HgCl2 that was partially reversed by β-mercaptoethanol. Further, root hydraulic conductivity of RAC875 was found to be lower than Kukri's and root cross-sections of RAC875 had significantly smaller stele and central metaxylem diameters. These findings indicate that the water-conservation of RAC875 results from a root-based hydraulic restriction that requires potentially heritable functional and anatomical features. The study revealed links between anatomical and AQP-based processes in regulating TR under increasing evaporative demand.
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Affiliation(s)
- R My Schoppach
- Earth and Life Institute-Agronomy, Université catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
| | - Diego Wauthelet
- Graduate School of Biological, Agricultural and Environmental Engineering, Université catholique de Louvain, Belgium
| | - Linda Jeanguenin
- Institut des Sciences de la Vie, Université catholique de Louvain, Croix du Sud 4, L7.07.14, 1348 Louvain-la-Neuve, Belgium
| | - Walid Sadok
- Earth and Life Institute-Agronomy, Université catholique de Louvain, Croix du Sud 2, L7.05.14, 1348 Louvain-la-Neuve, Belgium
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111
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Cabasan MTN, Kumar A, Bellafiore S, De Waele D. Histopathology of the rice root-knot nematode, Meloidogyne graminicola, on Oryza sativa and O. glaberrima. NEMATOLOGY 2014. [DOI: 10.1163/15685411-00002746] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The root-knot nematode, Meloidogyne graminicola, can cause substantial rice yield losses. Understanding the mechanisms of resistance to this nematode species in known resistant rice genotypes may help to improve rice genotypes, aiming at developing and implementing environment-friendly and cost-effective nematode management strategies. Using susceptible and resistant rice genotypes, a comparative analysis of histological response mechanisms was made during two phases of the nematode colonisation: i) root penetration; and ii) subsequent establishment and development by M. graminicola second-stage juveniles (J2). Two types of defence response mechanisms could be distinguished in the resistant rice genotypes. The early defence response consisted of a hypersensitive response (HR)-like reaction in the early stage of infection characterised by necrosis of cells directly affected by nematode feeding. This HR-like reaction was observed only in the M. graminicola-resistant Oryza glaberrima genotypes and not in the M. graminicola-susceptible O. sativa genotypes. The late defence response took place after the induction of giant cells by the J2. Giant cells usually collapsed and degenerated before J2 developed into adults. Structural features of the roots of the susceptible O. sativa showed greater root and stele diam. and cortex thickness than the resistant O. glaberrima genotypes. Desired features of plants with resistance to M. graminicola elucidated in this study can be used for selection of plants for breeding programmes.
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Affiliation(s)
- Ma. Teodora Nadong Cabasan
- 1Laboratory of Tropical Crop Improvement, Department of Biosystems, Faculty of Bioscience Engineering, University of Leuven (KU Leuven), Willem de Croylaan 42, 3001 Heverlee, Belgium
- 2Department of Biological Sciences, College of Arts and Sciences, University of Southern Mindanao, 9407 Kabacan, Cotabato, Philippines
- 3International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines
| | - Arvind Kumar
- 3International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines
| | - Stéphane Bellafiore
- 5IRD Institut de Recherche pour le Développement, UMR-186 Resistance des Plantes aux Bioagresseurs, IRD-Centre de Montpellier, Avenue Agropolis 911, BP 64501, F-34394 Montpellier Cedex 5, France
| | - Dirk De Waele
- 1Laboratory of Tropical Crop Improvement, Department of Biosystems, Faculty of Bioscience Engineering, University of Leuven (KU Leuven), Willem de Croylaan 42, 3001 Heverlee, Belgium
- 3International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines
- 4School of Environmental Sciences and Development, North-West University, Private Bag X6001, 2520 Potchefstroom, South Africa
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Comas LH, Becker SR, Cruz VMV, Byrne PF, Dierig DA. Root traits contributing to plant productivity under drought. FRONTIERS IN PLANT SCIENCE 2013. [PMID: 24204374 DOI: 10.3389/fenvs.2014.00442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less "leaky" and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding.
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Affiliation(s)
- Louise H Comas
- Water Management Research, United States Department of Agriculture-Agricultural Research Service Fort Collins, CO, USA
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Comas LH, Becker SR, Cruz VMV, Byrne PF, Dierig DA. Root traits contributing to plant productivity under drought. FRONTIERS IN PLANT SCIENCE 2013; 4:442. [PMID: 24204374 PMCID: PMC3817922 DOI: 10.3389/fpls.2013.00442] [Citation(s) in RCA: 476] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/15/2013] [Indexed: 05/17/2023]
Abstract
Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less "leaky" and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding.
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Affiliation(s)
- Louise H. Comas
- Water Management Research, United States Department of Agriculture-Agricultural Research ServiceFort Collins, CO, USA
| | - Steven R. Becker
- Department of Soil and Crop Sciences, Colorado State UniversityFort Collins, CO, USA
| | - Von Mark V. Cruz
- National Center for Genetic Resources Preservation, United States Department of Agriculture-Agricultural Research ServiceFort Collins, CO, USA
- Bioagricultural Sciences and Pest Management, Colorado State UniversityFort Collins, CO, USA
| | - Patrick F. Byrne
- Department of Soil and Crop Sciences, Colorado State UniversityFort Collins, CO, USA
| | - David A. Dierig
- National Center for Genetic Resources Preservation, United States Department of Agriculture-Agricultural Research ServiceFort Collins, CO, USA
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