{"title":"Ecophysiology of seed heteromorphism in halophytes: an overview.","authors":"R. Aysha, N. Farah, G Bilquees, M. Khan, H. Abdul","doi":"10.1079/9781786394330.0104","DOIUrl":"https://doi.org/10.1079/9781786394330.0104","url":null,"abstract":"Abstract\u0000 Seed heteromorphism is the production of two or more types of seeds by a single individual of many plant species. On the basis of an extensive literature survey, this chapter aims to provide an overview of the research on seed heteromorphism, especially in the context of halophytes, which are emerging as non-conventional crops for arid saline lands. We cover the occurrence, ecophysiological significance and different biochemical aspects of seed heteromorphism. Dormancy, and the responses of heteromorphic seeds of halophytes to salinity, temperature and photoperiod are discussed. We also provide an overview of the carryover effects of heteromorphic seeds to progeny. This article also attempts to highlight the gaps in existing knowledge about seed heteromorphism in halophytes.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133271900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Seagrasses, the unique adaptation of angiosperms to the marine environment: effect of high carbon and ocean acidification on energetics and ion homeostasis.","authors":"L. Rubio, J. A. Fernndez","doi":"10.1079/9781786394330.0089","DOIUrl":"https://doi.org/10.1079/9781786394330.0089","url":null,"abstract":"Abstract\u0000 As a functional group, seagrasses form highly productive ecosystems present along the coasts of all continents (except Antarctica), where they rival tropical rainforests and coral reefs in ecosystem services (Costanza et al., 1997; Fourqurean et al., 2012). Unfortunately, seagrasses are diminishing worldwide and several studies confirm a lack of appreciation for the value of these systems (Cullen-Unsworth et al., 2014). Since the last century, the effects of climate change on natural and agricultural terrestrial plant communities have already received significant attention, but relatively little emphasis has been given to aquatic plant communities, including seagrasses (Koch et al., 2013). Here we analyse the potential impact of global atmospheric CO2 increase on the adaptation mechanisms of these vascular plants to marine environments, highlighting the effects on membrane energization, nutrient uptake and cytosolic ion homeostasis.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123422645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Habitats of halophytes.","authors":"A. Kapler","doi":"10.1079/9781786394330.0019","DOIUrl":"https://doi.org/10.1079/9781786394330.0019","url":null,"abstract":"Abstract Salt-tolerant plants occur all over the world in a number of different ecosystems, ranging from pristine alkaline semi-deserts and mangrove forests; through semi-natural meadows and pastures; to man-made habitats such as the environs of graduation towers; over irrigated arable lands with poor drainage in the tropics; and to city lawns in the boreo-temperate zone polluted with NaCl and CaCl2 during deicing. Natural habitats disappear because of urbanization, tourism and agriculture intensification. Since 1980 one-fifth of the Earth's mangrove biome has disappeared as well as more than one-half of alkaline steppes and nearly all Earth's coastal and inland salt meadows, glassworts and other annual communities of muds and sands, Mediterranean and warm Atlantic halophilous scrubs, vegetated sea cliffs and machairs. At the same time halophytes colonize new, man-made habitats, becoming dominant or even the sole species there. Some salt-resistant species, such as Rhizophora mangle in Hawaii and Spartina anglica in the UK, become dangerous invasive species. Mangrove swamps deserve more efficient conservation and restoration efforts since they shelter coasts from erosion, tsunami and storm surge; trap a wide variety of heavy metals; and provide habitats for juvenile fish, oysters and crustaceans. In the temperate and boreal zones the traditional land use of saline meadows and pastures needs to be maintained to preserve the original biodiversity and ecosystem services. Further halophyte domestication will lead to establishment of completely new, artificial agro-ecosystems to yield food, fodder and fuel, as well as fibre and phytoremediation, for rapidly expanding human populations. A range of halophyte crop cultivation systems can help to reduce damage caused by salinization of soils and freshwater, increase food production up to 70% by 2050 and combat coastal erosion in the era of climate change and global pollinator crisis. At the same time we need to eradicate some monospecific thickets built by invasive, alien halophytes to restore primeval, species-rich communities in areas of naturally high salinity.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132509283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Salt marsh plants: biological overview and vulnerability to climate change.","authors":"B. Touchette, M. Kneppers, C. Eggert","doi":"10.1079/9781786394330.0115","DOIUrl":"https://doi.org/10.1079/9781786394330.0115","url":null,"abstract":"Abstract\u0000 Salt marshes are vegetative ecosystems that occupy intertidal zones in estuaries or behind coastal barrier islands where there is some degree of protection from strong wave energy. Physiochemical properties of these marshes are stressful for most angiosperms, as only a few species can tolerate the anoxic, chemically reduced, high-saline soils typical of these ecosystems. Despite the dynamic properties that make salt marshes inhospitable to most plants, they maintain some of the highest levels of biological productivity observed in nature. The vast majority of salt marsh halophytes do not require environmental salts to grow or reproduce, and only a few species are restricted to salinities greater than 0.5%. For salt marsh plants, tolerance to high salinities may involve multiple physiological strategies including ion compartmentalization, synthesis of compatible solutes, changes in membrane and/or cell wall properties, and/or salt exudation by way of salt glands or bladders. Even though salt marsh halophytes are well adapted to highly dynamic and, often, stressful environmental conditions, it is generally recognized that climate change will result in a global net loss of these ecologically and economically important ecosystems. Sea-level rise may decrease overall plant diversity by selecting species that are more tolerant to sustained flooding, or through the loss of mid- and high-marsh species that are less competitive to changing conditions. In areas where soil accretion fails to keep pace with rising waters and/or where landward migration is impeded, rising sea levels are likely to promote the conversion of marshes into unvegetated open water systems. Soil and water hypersalinity may also foster salt marsh die-offs in areas that are expected to experience seasonal declines in precipitation. Nevertheless, because of the natural complexity of these systems, the degree of salt marsh loss remains uncertain. Localized differences in climate, geology, hydrology and topography, along with biological and anthropogenic interactions, are likely to determine which marshes withstand the challenges of climate change and which marshes will be lost.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131984190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. B. Sghaier, S. Pedro, B. Duarte, I. Caador, N. Sleimi
{"title":"Arsenic tolerance mechanisms in halophytes: the case of Tamarix gallica.","authors":"D. B. Sghaier, S. Pedro, B. Duarte, I. Caador, N. Sleimi","doi":"10.1079/9781786394330.0255","DOIUrl":"https://doi.org/10.1079/9781786394330.0255","url":null,"abstract":"Abstract\u0000 Toxic compounds in the ecosphere are the consequence of environmental pollution, and have a disruptive influence in the environment. They affect ecosystems, entering food chains and ultimately touching human health. Metal consumption has increased by 300% in the last 50 years and the anthropogenic release of metallic elements such as Pb, Hg, As, Cd, Al and Cr has increased since the beginning of the industrial era. Different strategies have been identified to overcome metallic stress. Knowledge of plant stress responses and adaptations at physiological, biochemical and cellular levels is a priority in understanding the impact of these constraints on plant biodiversity. These adaptations have evolved naturally in halophytes as responses to their colonization of saline ecosystems, and therefore make halophytes good model plants. In this chapter we discuss the biophysical mechanisms underlying energy capture and transduction in halophytes and their relation to pigment profile alteration, compartmentation and subcellular localization, to devise sustainable strategies for environmental or ecosystem management and safety.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131711269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ion accumulation pattern of halophytes.","authors":"D. Chaudhary","doi":"10.1079/9781786394330.0137","DOIUrl":"https://doi.org/10.1079/9781786394330.0137","url":null,"abstract":"Abstract\u0000 Halophytes grow near the seashore, and in intertidal zones, coastal salt marshes, inland salt lakes and saline deserts under high salinity. They have socio-ecological values through their primary production, nutrient cycling, provision of wildlife habitats and stabilization of shorelines. Halophytes have attracted special attention from scientists because of their remarkable ability to tolerate higher salinity. This chapter summarizes current knowledge about ion absorption and accumulation patterns in the halophytes. These plants have different mechanisms to withstand salinity, such as succulence, salt exclusion, compartmentalization, compatible solutes and hair bladders. Halophytes that maintain higher K+/Na+ and Ca+2/Na+ ratios in their tissues are more tolerant of salinity. The electrical conductivity (salt concentration) of soils correlates well with Na+ concentrations in halophytes, and elevated soil salinity reduces halophyte species diversity.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115604596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thylakoid electron transfer in Salicornia veneta under different salinity levels: a fluorescence-based study.","authors":"R. Cannata, R. Barbato","doi":"10.1079/9781786394330.0266","DOIUrl":"https://doi.org/10.1079/9781786394330.0266","url":null,"abstract":"Abstract\u0000 The halophyte Arthrocnemum macrostachyum is able to survive in extreme environments where salt concentrations may rise to 1 M NaCl. Here we report the results of a study in which the photochemical properties of both photosystem (PS) PSII and PSI have been investigated in individuals living in their natural environment (Sacca di Bellocchio, Prato Zangheri, Ravenna, Italy) by using Pulse amplitude modulation and fast fluorescence techniques. Results from quenching analysis (for both photosystems) and fluorescence decay in the sub-millisecond range (for PSII) are reported and discussed in terms of adaptation mechanism(s) of these plants to this extreme environment.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"358 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115942184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Introgression of halophytic salt stress-responsive genes for developing stress tolerance in crop plants.","authors":"R. Jha, P. Jaykumar, M. Avinash, J Bhavanath","doi":"10.1079/9781786394330.0275","DOIUrl":"https://doi.org/10.1079/9781786394330.0275","url":null,"abstract":"Abstract\u0000 The world's population is increasing daily, with corresponding demands for sustainable food production, but about 800 million ha of land is affected by salt. Salinization is gradually increasing for several reasons, including scanty rainfall, poor irrigation practices, salt ingression and natural calamities. Salinity is considered a major abiotic stress that adversely affects the growth and productivity of crop plants. Commonly, crop plants are salt sensitive (glycophytes) and so cannot grow in the salt-affected areas. Some plants have natural ability to grow in the high saline areas and are known as halophytes. Halophytes require salt to complete their life cycle and are thus considered potential sources for salt-responsive genes and promoters. The salt-tolerance mechanism is a very complex process which is coordinated from stress perception to signal transduction, and thus provides stress endurance. Several potential salinity-stress responsive and tolerance genes have been isolated from halophytes, functionally characterized and explored for developing transgenic crop plants for sustainable agriculture in the salt-affected areas. About one-quarter of the entire Arabidopsis genome responds to salt stress, and so the search continues for promising stress-responsive genes that can modulate physiological traits and metabolic pathways without imposing yield penalties. This chapter focuses on the examination of halophytes for salt-responsive genes, their functional validation and further utilization to engineer crop plants.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126458091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Halophytes: potential resources of coastal ecosystems and their economic, ecological and bioprospecting significance.","authors":"A. Parida, K. Asha, R Jaykumar, P. Monika","doi":"10.1079/9781786394330.0287","DOIUrl":"https://doi.org/10.1079/9781786394330.0287","url":null,"abstract":"Abstract\u0000 Halophytes are a special group of plants that grow and flourish in highly saline environments. This chapter summarizes current knowledge exploring the enormous potential of halophytes for industrial applications in the form of nutraceuticals, essential oils, biofuels, alcohol, latex, cosmetics, fibres, etc., and the bioactive molecules rendering these properties. We critically analyse recent literature addressing halophytes as a potential source of valuable metabolites having nutraceutical and pharmaceutical value, and their potential for remediating nutrient-rich effluents from coastal aquaculture. The growing body of evidence discussed in this chapter supports the perception that halophytes can be incorporated easily into saltwater-based agriculture as a source of high-value products. Bioprospecting the biomedical compounds isolated from halophytes promises to help in the sustainable commercialization of the identified bioactive compounds. Cultivation of halophytes is both economically and ecologically beneficial: it encourages the extension of technologies to improve a country's economy by providing employment opportunities, and also helps to protect coastal wastelands and promotes ecosystem restoration. We discuss the ecological, economic, nutraceutical and therapeutic potential of halophytes, focusing on the primary and secondary bioactive compounds or metabolites applicable to nutraceuticals, pharmaceuticals or cosmetic applications; and also explore the potential of halophytes for reclamation of salt-affected and heavy metal-contaminated lands.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125309773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Soil chemical composition modifies the morpho-physiological responses of Prosopis strombulifera, a halophyte native to South America.","authors":"M. Reginato, A. Llanes, V. Luna","doi":"10.1079/9781786394330.0209","DOIUrl":"https://doi.org/10.1079/9781786394330.0209","url":null,"abstract":"Abstract\u0000 In some salty areas of South America, and especially in central Argentina, high levels of sodium sulfate (Na2SO4) are found together with sodium chloride (NaCl). Plant species show differences in their susceptibility to growth in the presence of these salts. Some studies showed that Na2SO4 may inhibit the growth of species such as wheat, sugarcane, beet, tomato, wild potato and barley more than NaCl. However, studies focusing on how sodium sulfate can affect the biochemical and physiological processes of plants are very scarce. This chapter provides an overview of the tolerance/non-tolerance mechanisms of the halophyte Prosopis strombulifera, with a special emphasis on the effects of Na2SO4 on growth parameters, ion accumulation, production of secondary metabolites, antioxidant system and hormonal regulation, showing that the presence of the SO42- anion in the culture medium was determinant in the toxicity observed in P. strombulifera plants treated with Na2SO4. It is proposed that, as SO42- assimilation may be limited by the high concentration in the culture medium, the sulfur that has not been metabolized to cysteine would be in excess; it may be binding to cytochrome b559 of PSII, blocking its activity partially or completely, and thus inhibiting photosynthesis. Carbon metabolism and partitioning of Na2SO4 treated plants are also affected, and energy resources should be diverted to synthesis of secondary metabolites such as condensed tannins and lignin, and polyphenol precursors, to cope with the high oxidative stress. As a consequence, there is a strong inhibition in the growth of Na2SO4 treated plants, leading to chlorosis, necrosis and foliar abscission.","PeriodicalId":285820,"journal":{"name":"Halophytes and climate change: adaptive mechanisms and potential uses","volume":"8 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120990687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}