Plant Responses

6 Key excerpts on "Plant Responses"

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  eBook - PDF

  Abiotic Stress

  Plant Responses and Applications in Agriculture

  • Kourosh Vahdati, Charles Leslie, Kourosh Vahdati, Charles Leslie(Authors)
  • 2013(Publication Date)
  • IntechOpen

    (Publisher)

  The ability of plants to adapt and/or acclimate to different environments is directly or indirectly related with the plasticity and resilience of photosynthesis, in combination with other processes, determining plant growth and development, namely reproduction [4]. A remarkable feature of plant adaptation to abiotic stresses is the activation of multiple responses involving complex gene interactions and crosstalk with many molecular pathways [5, 6]. Abiotic stresses elicit complex cellular responses that have been elucidated by progresses made in exploring and understanding plant abiotic responses at the whole-plant, physiological, biochemical, cellular and molecular levels [7]. One of the biggest challenges to modern sustainable agriculture development is to obtain new knowledge that should allow breeding and engineering plants with new and desired agronomical traits [8]. The creation of stress-tolerant crop either by genetic engineering or through conventional breeding covered almost all aspects of plant science, and is pursued by both public and private sector researchers [9]. © 2013 Duque et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Duque et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. During the last decade, our research groups have focused their research on elucidating the different components and molecular players underlying abiotic stress responses of a broad range of species both model and crops plant.

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  Plant Biochemistry

  • P. M. Dey, J. B. Harborne(Authors)
  • 1997(Publication Date)
  • Academic Press

    (Publisher)

  That plants have survived so well is due to their enormous flexibility to adapt to the diversity of growth conditions and environments that are present on this planet. Plants have adapted by modifying morphological and anatomical features (e.g. spines instead of leaves in desert habitats), through physiological adaptation (e.g. by reducing transpiration under a hot midday sun) or by biochemical means. In recent years, increasing attention has been paid to the ways that plants are biochemically adapted to their differing environments. Biochemical adaptation may involve both primary and secondary metabolism. It may be focused on environmental variables (drought, frost, salinity, heavy metal toxicity) or on the response of plants to other forms of life, whether they be bacteria, fungi, insects, molluscs or grazing mammals.

  The study of biochemical adaptation of plants to ecological factors is the subject matter of ecological biochemistry, or chemical ecology as it is often termed (Harborne, 1993 ). The purpose of this chapter is to provide a general introduction to such biochemistry. The emphasis will naturally be on the plant and its responses, although much of the literature of plant–animal interactions has been concerned with animals (especially insects) rather than with plants. Plant–microbial interactions will not be considered here since they are the subject matter of Chapter 13 .

  The first section of this chapter will deal with plant adaptation to climatic and edaphic factors in the natural environment. The second section will consider the various toxins produced constitutively by plants in response to pressures of herbivory. The third section will discuss how far the distribution patterns of these toxins which accumulate in plants are correlated with a defensive role. The fourth and final section will be devoted to the ways that plants can respond dynamically to the damaging effects of grazing animals by producing new chemicals, becoming unpalatable in the process.

  14.2 Plant Responses TO THE ENVIRONMENT

  The biochemical responses of plants to various forms of environmental stress are listed in Table 14.1 . Each response involves one or more changes in the biochemistry of the plant cell. Thus it may require the development of a new metabolic pathway. This happens in the case of photosynthetic adaptation to subtropical and tropical climates, when the Hatch–Slack C4 cycle comes into operation (Chapter 2

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  Plant Stress Biology

  Progress and Prospects of Genetic Engineering

  • Arindam Kuila(Author)
  • 2020(Publication Date)
  • Apple Academic Press

    (Publisher)

  The increase in population and commercialization of life’s basic needs has increased demands for space and food supply. The combined effect of deforestation and pollution has led to the high activity of both natural and man-made stress to plants, making farmers to rely heavily on pesticides and herbicides. Over time, this had significant effects on both the plants and the type of stress. The weeds, pests, and pathogens have grown tolerant and adapted to the chemicals, whereas the plants have lost its yield capacity. Research into a biophysical and molecular modification of plants for tolerating stress and increased yield has revived hope, but the unavailability of the modified seeds to farmers in the developing countries has set an upsetting pretext, to begin with. This misbalance, in turn, has set a domino effect on the global economy (Mosa et al., 2017).

  In the natural environment, plants have to undergo a range of different and complex interactions, which they have achieved through evolution. Along with this, the plants have also acquired several mechanisms to counteract the various stress conditions in nature. Stress induces mainly metabolic distress within the plant system whose effect can be witnessed through the physiological changes and productivity (Rejeb et al., 2014). These responses are complex and intense and include a vast array of different cellular and molecular adaptations. Plants have developed individual responses to different kinds of stress, which under adverse conditions can cross-talk and eventually lead to a cascade of signaling pathways. Throughout the years, stress has been broadly classified into biotic and abiotic stress, which wreaks havoc in the metabolism of plants when exposed to it, leading to physiological disruption (Mosa et al., 2017).

  Abiotic stress is most important as it causes more harm leading to >50% losses in the field, whereas biotic stress is a challenge as it leads to more damage through pathogen and herbivore attack. Over the years, research has shown the development of various defense mechanisms in response to stress in a quick and efficient manner (Rejeb et al., 2014). After recognizing the stress, plants introduce a series of molecular mechanisms including the opening of ion channels, activation of signaling cascades, production of reactive oxygen species (ROS) and phytohormones, which ultimately leads to a change in the genetic programming, thus increasing the tolerance of the plant, meanwhile decreasing biological and physiological damage caused by the stress (Kissoudis et al., 2014).

  Interestingly, research has shown that plants witness multiple stress when in the field or in natural conditions. This leads to multiple responses, which may be additive, synergistic, or antagonistic. Under continuous stress, plants grow resistant to various stresses and produce a response for single stress, proving the existence of cross-tolerance and the ability of plants to possess a powerful regulatory response against the changing environment (Atkinson and Urwin, 2012).

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  Plant Sensing and Communication

  • Richard Karban(Author)
  • 2015(Publication Date)
  • University of Chicago Press

    (Publisher)

  5

  Plant Responses to Cues about Resources

  5.1 General characteristics of Plant Responses

  Plants both produce and respond to many cues. These cues provide the plant with information about resources that occur heterogeneously throughout the landscape. In some instances we understand the basic nature of those cues and the receptor systems that plants use to perceive them; these were outlined in the previous chapters. In this chapter we will consider the morphological, chemical, and behavioral phenotypic responses that plants exhibit when faced with cues indicating environmental heterogeneity in the levels of potential resources. Research indicates that plants selectively place their semiautonomous units (such as root, shoot, and stem modules) to respond to local conditions above and below ground, ranging from light availability to distribution of nutrients in the soil. The types of behaviors plants exhibit in response to cues are complex and varied. Because plants are faced with multiple cues, they even demonstrate the ability to make decisions about which cue to respond to when a trade-off is necessary.

  Environmental conditions that are important to plants vary over space and time. Plants respond to cues that reliably indicate current or future conditions to adjust their phenotypes to match these variable environments. Phenotypic adjustments may take the form of plant movements, physiological acclimation, growth of new tissues and organs, or shedding of existing tissues and organs. These responses may be considered behaviors if they occur in response to a stimulus, are reversible, and occur rapidly within the lifespan of an individual (Silvertown and Gordon 1989, Karban 2008) (see chapter 1 ).

  Morphological responses of plants are possible in many instances because plants are made up of repeated semiautonomous modules (White 1979, Silvertown and Gordon 1989, Herrera 2009). These modules are produced by reiterated meristems that can give rise to multiple organs of undetermined characteristics that can vary in type, size, shape, number, and function. As a result, plants are sometimes able to quickly and radically transform in response to different cues. Since plants tend to be less mobile than animals, a plastic morphology allows some of the flexibility that is lost by being rooted in one place. In addition to growing in one direction or another, plants also adjust their morphologies by shedding or abscising tissues and organs that are not as productive or valuable.

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  Plant, Abiotic Stress and Responses to Climate Change

  • Violeta Andjelkovic(Author)
  • 2018(Publication Date)
  • IntechOpen

    (Publisher)

  The interaction of plants with the stress-inducing environments has produced in the plants a set of adaptive responses that can be studied in different description scopes: from organelles and subcellular structures to the level of plant communities. When it occurs for short time or low intensity, environmental stress can induce hardening , followed by induction of tolerance; on the other hand, when the plant´s reaction is for a long time or responding to a significant stress intensity, the response of plants includes decreased growth, depletion of metabolic reserves and loss of productivity and yield, even reaching the death of plants. Current knowledge about these crop responses can be translated into agronomic practices aimed at mitigating the adverse effects of environmental stress. This chapter will present the mechanisms of response and adaptation of crop plants to the environmental factors that most commonly cause crop damage or yield loss: high and low temperature, salinity, water deficit and nutrient deficits. Agronomic practices aimed at modifying or balancing some of the envi -ronmental factors involved and the use of tolerance induction techniques are described. Keywords: hardening, stress hardiness, biostimulation, abiotic stress, multiple stresses © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction Climate change is a reality that we must address using technology, scientific knowledge, and economic and social policies that modify the relationship between human society and its envi-ronment.

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  Stress Physiology of Woody Plants

  • Wenhao Dai(Author)
  • 2019(Publication Date)
  • CRC Press

    (Publisher)

  Woody plants, unlike herbaceous annual plants, are more often exposed to various biotic and abiotic stresses due to their perennial characteristics. As sessile organisms, woody plants have evolved a series of intricate mechanisms that allow them to perceive external signals and respond to complicated stress conditions, resulting in minimum damage while conserving valuable resources for growth, development and reproduction. Phytohormones such as abscisic acid (ABA), ethylene (ET), jasmonic acid (JA), and salicylic acid (SA) primarily regulate the protective responses of plants against both biotic and abiotic stresses via synergistic and antagonistic actions that are referred to as signaling crosstalk (Fujita et al., 2006). Research has shown that reactive oxygen species (ROS), nitric oxide (NO) and sugars such as glucose are key signal molecules in responses to multiple stresses (Sheen et al., 1999; Neill et al., 2002). There is increasing evidence that unique combinations of multiple stresses often trigger interactive signaling pathways from various phytohormones and other signal molecules or antioxidants, resulting in distinct transcriptional activation patterns during biotic and abiotic stresses (Shoji and Hashimoto, 2015). Therefore, present techniques of individually imposing each stress in a test to develop stress-tolerant plants may be inadequate.

  Large-scale transcriptome analyses strongly support that biotic and abiotic stresses often regulate the expression of multiple overlapping genes in many signaling networks. For instance, the analysis of the correlation between the transcriptional regulation by environmental challenges (e.g. jasmonate application) and by incompatible pathogen infection revealed the expression of considerable overlapping genes in response (Luu et al., 2015). These data suggested that crosstalk between these signaling networks was involved in triggering downstream stress responses. Thus, there is increasing evidence that plant signaling pathways consist of elaborate networks with frequent crosstalk, and, consequently, allow plants to improve both abiotic stress tolerance and disease resistance. In this review, functional genes that are involved in crosstalk and molecular convergence points between biotic and abiotic stress signaling pathways are discussed.

  11.2  Physiological Response to Multiple Stresses

  Abiotic and biotic stresses, such as salinity, drought, oxidative stress, wounding and pathogen attack, are serious threats to plant growth development, causing reduced yield and quality in many plants including woody species. Although intensive research has been done in the field of plant response to stresses, very limited research has focused on Plant Responses to individual biotic and abiotic factors (Hu et al., 2016a). Due to their perennial nature, woody plants often encounter combinations of diverse stresses arising from various sources (Mahalingam, 2015). The physiological performance of woody plants largely depends on environmental factors including light, temperature, water and air conditions. The effects of these environmental factors on plant functions may often be interactive rather than additive (Sun et al., 2016); therefore, studies of physiological responses of woody plants to multifactorial stresses are very important.

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