{"title":"Inducible tolerance to low Ca:Mg in serpentine ecotype of Erythranthe guttata","authors":"","doi":"10.1016/j.jplph.2024.154355","DOIUrl":null,"url":null,"abstract":"<div><div>In serpentine soils, the low level of calcium relative to magnesium (Ca:Mg) is detrimental to the growth of most plant species. Ecotypic variation in <em>Erythranthe guttata</em> allows for some populations to maintain high photosynthetic rates and biomass despite low Ca:Mg. In this study, the mechanism of tolerance was investigated by treating hydroponically grown plants with either high (1.0) or low (0.02) Ca:Mg growth solutions and assaying excised leaf discs for rates of photosynthesis and disc expansion, and for starch, Ca<sup>2+</sup> and Mg<sup>2+</sup> ion concentrations. Low Ca:Mg in the assay solutions reduced both photosynthesis and leaf disc expansion after one week of treatment. However, serpentine tissues show stable photosynthetic rates after one week and a recovery in leaf tissue expansion after two weeks exposure to low Ca:Mg conditions. Values for non-serpentine tissues continued to decline. Increased growth of low Ca:Mg treated discs supplied with exogenous sucrose suggests that growth in serpentine-exposed tissues is limited by availability of carbon products from photosynthesis. Serpentine leaves had higher vacuole Mg concentrations than non-serpentine leaves after three weeks of treatment with low Ca:Mg. The combination of elevated starch concentrations, reduced growth and lower vacuolar Mg concentrations in leaves of non-serpentine plants grown in low Ca:Mg indicate an inefficient use of carbon resources and starch degradation as an observed response to Mg toxicity. Together, these results suggest that serpentine <em>E. guttata</em> exhibits an inducible tolerance to low Ca:Mg through gradual compartmentalization of magnesium to maintain the production and metabolism of photosynthates necessary for growth.</div></div>","PeriodicalId":16808,"journal":{"name":"Journal of plant physiology","volume":null,"pages":null},"PeriodicalIF":4.0000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of plant physiology","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S017616172400186X","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
In serpentine soils, the low level of calcium relative to magnesium (Ca:Mg) is detrimental to the growth of most plant species. Ecotypic variation in Erythranthe guttata allows for some populations to maintain high photosynthetic rates and biomass despite low Ca:Mg. In this study, the mechanism of tolerance was investigated by treating hydroponically grown plants with either high (1.0) or low (0.02) Ca:Mg growth solutions and assaying excised leaf discs for rates of photosynthesis and disc expansion, and for starch, Ca2+ and Mg2+ ion concentrations. Low Ca:Mg in the assay solutions reduced both photosynthesis and leaf disc expansion after one week of treatment. However, serpentine tissues show stable photosynthetic rates after one week and a recovery in leaf tissue expansion after two weeks exposure to low Ca:Mg conditions. Values for non-serpentine tissues continued to decline. Increased growth of low Ca:Mg treated discs supplied with exogenous sucrose suggests that growth in serpentine-exposed tissues is limited by availability of carbon products from photosynthesis. Serpentine leaves had higher vacuole Mg concentrations than non-serpentine leaves after three weeks of treatment with low Ca:Mg. The combination of elevated starch concentrations, reduced growth and lower vacuolar Mg concentrations in leaves of non-serpentine plants grown in low Ca:Mg indicate an inefficient use of carbon resources and starch degradation as an observed response to Mg toxicity. Together, these results suggest that serpentine E. guttata exhibits an inducible tolerance to low Ca:Mg through gradual compartmentalization of magnesium to maintain the production and metabolism of photosynthates necessary for growth.
期刊介绍:
The Journal of Plant Physiology is a broad-spectrum journal that welcomes high-quality submissions in all major areas of plant physiology, including plant biochemistry, functional biotechnology, computational and synthetic plant biology, growth and development, photosynthesis and respiration, transport and translocation, plant-microbe interactions, biotic and abiotic stress. Studies are welcome at all levels of integration ranging from molecules and cells to organisms and their environments and are expected to use state-of-the-art methodologies. Pure gene expression studies are not within the focus of our journal. To be considered for publication, papers must significantly contribute to the mechanistic understanding of physiological processes, and not be merely descriptive, or confirmatory of previous results. We encourage the submission of papers that explore the physiology of non-model as well as accepted model species and those that bridge basic and applied research. For instance, studies on agricultural plants that show new physiological mechanisms to improve agricultural efficiency are welcome. Studies performed under uncontrolled situations (e.g. field conditions) not providing mechanistic insight will not be considered for publication.
The Journal of Plant Physiology publishes several types of articles: Original Research Articles, Reviews, Perspectives Articles, and Short Communications. Reviews and Perspectives will be solicited by the Editors; unsolicited reviews are also welcome but only from authors with a strong track record in the field of the review. Original research papers comprise the majority of published contributions.