51
|
Ismail H, Dragišic Maksimovic J, Maksimovic V, Shabala L, Živanovic BD, Tian Y, Jacobsen SE, Shabala S. Rutin, a flavonoid with antioxidant activity, improves plant salinity tolerance by regulating K + retention and Na + exclusion from leaf mesophyll in quinoa and broad beans. FUNCTIONAL PLANT BIOLOGY : FPB 2015; 43:75-86. [PMID: 32480443 DOI: 10.1071/fp15312] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/01/2015] [Indexed: 05/20/2023]
Abstract
The causal relationship between salinity and oxidative stress tolerance is well established, but specific downstream targets and the role of specific antioxidant compounds in controlling cellular ionic homeostasis remains elusive. In this work, we have compared antioxidant profiles of leaves of two quinoa genotypes contrasting in their salt tolerance, with the aim of understanding the role of enzymatic and non-enzymatic antioxidants in salinity stress tolerance. Only changes in superoxide dismutase activity were correlated with plant adaptive responses to salinity. Proline accumulation played no major role in either osmotic adjustment or in the tissue tolerance mechanism. Among other non-enzymatic antioxidants, rutin levels were increased by over 25 fold in quinoa leaves. Exogenous application of rutin to glycophyte bean leaves improved tissue tolerance and reduced detrimental effects of salinity on leaf photochemistry. Electrophysiological experiments revealed that these beneficial effects were attributed to improved potassium retention and increased rate of Na+ pumping from the cell. The lack of correlation between rutin-induced changes in K+ and H+ fluxes suggest that rutin accumulation in the cytosol scavenges hydroxyl radical formed in response to salinity treatment thus preventing K+ leak via one of ROS-activated K+ efflux pathways, rather than controlling K+ flux via voltage-gated K+-permeable channels.
Collapse
Affiliation(s)
- Hebatollah Ismail
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Jelena Dragišic Maksimovic
- Institute for Multidisciplinary Studies, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
| | - Vuk Maksimovic
- Institute for Multidisciplinary Studies, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
| | - Lana Shabala
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Branka D Živanovic
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Yu Tian
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Sven-Erik Jacobsen
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Sergey Shabala
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| |
Collapse
|
52
|
Paz RC, Reinoso H, Espasandin FD, González Antivilo FA, Sansberro PA, Rocco RA, Ruiz OA, Menéndez AB. Akaline, saline and mixed saline-alkaline stresses induce physiological and morpho-anatomical changes in Lotus tenuis shoots. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16:1042-9. [PMID: 24597843 DOI: 10.1111/plb.12156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 12/19/2013] [Indexed: 05/09/2023]
Abstract
Saline, alkaline and mixed saline-alkaline conditions frequently co-occur in soil. In this work, we compared these plant stress sources on the legume Lotus tenuis, regarding their effects on shoot growth and leaf and stem anatomy. In addition, we aimed to gain insight on the plant physiological status of stressed plants. We performed pot experiments with four treatments: control without salt (pH = 5.8; EC = 1.2 dS·m(-1)) and three stress conditions, saline (100 mM NaCl, pH = 5.8; EC = 11.0 dS·m(-1)), alkaline (10 mM NaHCO3, pH = 8.0, EC = 1.9 dS·m(-1)) and mixed salt-alkaline (10 mM NaHCO3 + 100 mM NaCl, pH = 8.0, EC = 11.0 dS·m(-1)). Neutral and alkaline salts produced a similar level of growth inhibition on L. tenuis shoots, whereas their mixture exacerbated their detrimental effects. Our results showed that none of the analysed morpho-anatomical parameters categorically differentiated one stress from the other. However, NaCl- and NaHCO3 -derived stress could be discriminated to different extents and/or directions of changes in some of the anatomical traits. For example, alkalinity led to increased stomatal opening, unlike NaCl-treated plants, where a reduction in stomatal aperture was observed. Similarly, plants from the mixed saline-alkaline treatment characteristically lacked palisade mesophyll in their leaves. The stem cross-section and vessel areas, as well as the number of vascular bundles in the sectioned stem were reduced in all treatments. A rise in the number of vessel elements in the xylem was recorded in NaCl-treated plants, but not in those treated exclusively with NaHCO3.
Collapse
Affiliation(s)
- R C Paz
- Unidad de Biotecnología 1, IIB-IINTECH/UNSAM-CONICET, Chascomús, Buenos Aires, Argentina; Facultad de Ciencias Agrarias (FCA), Instituto de Biotecnología Agrícola de Mendoza (IBAM), Mendoza, Argentina
| | | | | | | | | | | | | | | |
Collapse
|
53
|
LoPresti EF. Chenopod salt bladders deter insect herbivores. Oecologia 2013; 174:921-30. [PMID: 24241642 DOI: 10.1007/s00442-013-2827-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 10/31/2013] [Indexed: 11/28/2022]
Abstract
Trichomes on leaves and stems of certain chenopods (Chenopodiaceae) are modified with a greatly enlarged apical cell (a salt bladder), containing a huge central vacuole. These structures may aid in the extreme salt tolerance of many species by concentrating salts in the vacuole. Bladders eventually burst, covering the leaf in residue of bladder membranes and solid precipitates. The presence of this system in non-halophytic species suggests additional functions. I tested the novel hypothesis that these bladders have a defensive function against insect herbivores using choice, no choice, and field tests. Generalist insect herbivores preferred to feed on leaves without salt bladders in choice tests. In no choice tests, herbivores consumed less leaf matter with bladders. In a field test, leaves from which I had removed bladders suffered greater herbivory than adjacent leaves with bladders. Solutions containing bladders added to otherwise preferred leaves deterred herbivores, suggesting a water-soluble chemical component to the defense. This bladder system has a defensive function in at least four genera of chenopods. Salt bladders may be a structural defense, like spines or domatia, but also have a chemical defense component.
Collapse
Affiliation(s)
- E F LoPresti
- Department of Entomology, Graduate Group in Ecology, Center for Population Biology, University of California-Davis, Davis, CA, USA,
| |
Collapse
|
54
|
Shabala S. Learning from halophytes: physiological basis and strategies to improve abiotic stress tolerance in crops. ANNALS OF BOTANY 2013; 112:1209-21. [PMID: 24085482 PMCID: PMC3806534 DOI: 10.1093/aob/mct205] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 07/22/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND Global annual losses in agricultural production from salt-affected land are in excess of US$12 billion and rising. At the same time, a significant amount of arable land is becoming lost to urban sprawl, forcing agricultural production into marginal areas. Consequently, there is a need for a major breakthrough in crop breeding for salinity tolerance. Given the limited range of genetic diversity in this trait within traditional crops, stress tolerance genes and mechanisms must be identified in extremophiles and then introduced into traditional crops. SCOPE AND CONCLUSIONS This review argues that learning from halophytes may be a promising way of achieving this goal. The paper is focused around two central questions: what are the key physiological mechanisms conferring salinity tolerance in halophytes that can be introduced into non-halophyte crop species to improve their performance under saline conditions and what specific genes need to be targeted to achieve this goal? The specific traits that are discussed and advocated include: manipulation of trichome shape, size and density to enable their use for external Na(+) sequestration; increasing the efficiency of internal Na(+) sequestration in vacuoles by the orchestrated regulation of tonoplast NHX exchangers and slow and fast vacuolar channels, combined with greater cytosolic K(+) retention; controlling stomata aperture and optimizing water use efficiency by reducing stomatal density; and efficient control of xylem ion loading, enabling rapid shoot osmotic adjustment while preventing prolonged Na(+) transport to the shoot.
Collapse
Affiliation(s)
- Sergey Shabala
- School of Agricultural Science, University of Tasmania, Private Bag 54, Hobart, Tas 7001, Australia
| |
Collapse
|
55
|
Sanoubar R, Orsini F, Gianquinto GP. Ionic partitioning and stomatal regulation: dissecting functional elements of the genotypic basis of salt stress adaptation in grafted melon. PLANT SIGNALING & BEHAVIOR 2013; 8:e27334. [PMID: 24309549 PMCID: PMC4091613 DOI: 10.4161/psb.27334] [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: 10/14/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 06/02/2023]
Abstract
Vegetable grafting is commonly claimed to improve crop's tolerance to biotic and abiotic stresses, including salinity. Although the use of inter-specific graftings is relatively common, whether the improved salt tolerance should be attributed to the genotypic background rather than the grafting per se is a matter of discussion among scientists. It is clear that most of published research has to date overlooked the issue, with the mutual presence of self-grafted and non-grafted controls resulting to be quite rare within experimental evidences. It was recently demonstrated that the genotype of the rootstock and grafting per se are responsible respectively for the differential ion accumulation and partitioning as well as to the stomatal adaptation to the stress. The present paper contributes to the ongoing discussion with further data on the differences associated to salinity response in a range of grafted melon combinations.
Collapse
Affiliation(s)
- Rabab Sanoubar
- Department of Agricultural Sciences; University of Bologna; Viale Fanin, Bologna, Italy
| | - Francesco Orsini
- Department of Agricultural Sciences; University of Bologna; Viale Fanin, Bologna, Italy
| | | |
Collapse
|
56
|
Orsini F, Sanoubar R, Oztekin GB, Kappel N, Tepecik M, Quacquarelli C, Tuzel Y, Bona S, Gianquinto G. Improved stomatal regulation and ion partitioning boosts salt tolerance in grafted melon. FUNCTIONAL PLANT BIOLOGY : FPB 2013; 40:628-636. [PMID: 32481136 DOI: 10.1071/fp12350] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/24/2013] [Indexed: 06/11/2023]
Abstract
Grafted plants are often more tolerant to salinity than nongrafted controls. In order to distinguish differential response components in grafted melon (Cucumis melo L.), salt stress was imposed on several rootstock-scion combinations in four experiments. The rootstock used was an interspecific squash (Cucurbita maxima Duch.×Cucurbita moschate Duch.), RS841, combined with two cantaloupe (C. melo var. cantalupensis) cultivars, namely London and Brennus, against both self-grafted and nongrafted controls. Physiological, morphological and biochemical adaptations to 0, 40 and 80mM NaCl were monitored. Upon salinity, plant biomass and leaf area were improved by grafting per se, since self-grafted plants performed similarly to the heterografted ones. However, improvements in the exclusion of Na+ and the uptake of K+ were due only to the rootstock genotype, since ionic composition was similar in self-grafted and nongrafted plants. These results indicate that the favourable effects of grafting on plant growth cannot be ascribed to a more efficient exclusion of Na+ or enhanced nutrient uptake. On the other hand, growth improvements in both self- and heterografted plants were associated with a more efficient control of stomatal functions (changes in stomatal index and water relations), which may indicate that the grafting incision may alter hormonal signalling between roots and shoots.
Collapse
Affiliation(s)
- Francesco Orsini
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 44, 40127 Bologna, Italy
| | - Rabab Sanoubar
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 44, 40127 Bologna, Italy
| | - Golgen Bahar Oztekin
- Department of Horticulture, Ege University, Faculty of Agriculture, 35100 Bornova, Izmir, Turkey
| | - Noemi Kappel
- Department of Vegetable and Mushroom Growing, Corvinus University of Budapest, Villányi str. 29, Budapest H-1118, Hungary
| | - Mahmut Tepecik
- Department of Soil and Plant Nutrition, Ege University, Faculty of Agriculture, 35100 Bornova, Izmir, Turkey
| | - Cristina Quacquarelli
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 44, 40127 Bologna, Italy
| | - Yuksel Tuzel
- Department of Horticulture, Ege University, Faculty of Agriculture, 35100 Bornova, Izmir, Turkey
| | - Stefano Bona
- University of Padova, Department of Environmental Agronomy and Crop Science, via Università 16, 35020 Legnaro, Padova, Italy
| | - Giorgio Gianquinto
- Department of Agricultural Sciences, Alma Mater Studiorum University of Bologna, Viale Fanin 44, 40127 Bologna, Italy
| |
Collapse
|
57
|
Shabala S, Hariadi Y, Jacobsen SE. Genotypic difference in salinity tolerance in quinoa is determined by differential control of xylem Na(+) loading and stomatal density. JOURNAL OF PLANT PHYSIOLOGY 2013; 170:906-14. [PMID: 23485259 DOI: 10.1016/j.jplph.2013.01.014] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/30/2013] [Accepted: 01/30/2013] [Indexed: 05/06/2023]
Abstract
Quinoa is regarded as a highly salt tolerant halophyte crop, of great potential for cultivation on saline areas around the world. Fourteen quinoa genotypes of different geographical origin, differing in salinity tolerance, were grown under greenhouse conditions. Salinity treatment started on 10 day old seedlings. Six weeks after the treatment commenced, leaf sap Na and K content and osmolality, stomatal density, chlorophyll fluorescence characteristics, and xylem sap Na and K composition were measured. Responses to salinity differed greatly among the varieties. All cultivars had substantially increased K(+) concentrations in the leaf sap, but the most tolerant cultivars had lower xylem Na(+) content at the time of sampling. Most tolerant cultivars had lowest leaf sap osmolality. All varieties reduced stomata density when grown under saline conditions. All varieties clustered into two groups (includers and excluders) depending on their strategy of handling Na(+) under saline conditions. Under control (non-saline) conditions, a strong positive correlation was observed between salinity tolerance and plants ability to accumulate Na(+) in the shoot. Increased leaf sap K(+), controlled Na(+) loading to the xylem, and reduced stomata density are important physiological traits contributing to genotypic differences in salinity tolerance in quinoa, a halophyte species from Chenopodium family.
Collapse
Affiliation(s)
- Sergey Shabala
- School of Agricultural Science, University of Tasmania, Private Bag 54, Hobart, Tas 7001, Australia.
| | | | | |
Collapse
|