Biotic and Abiotic Stresses in Plants

Abstract

Plants are subjected to a wide range of environmental stresses which reduces and limits the productivity of agricultural crops. Two types of environmental stresses are encountered to plants which can be categorized as (1) Abiotic stress and (2) Biotic stress. The abiotic stress causes the loss of major crop plants worldwide and includes radiation, salinity, floods, drought, extremes in temperature, heavy metals, etc. On the other hand, attacks by various pathogens such as fungi, bacteria, oomycetes, nematodes and herbivores are included in biotic stresses. As plants are sessile in nature, they have no choice to escape from these environmental cues. Plants have developed various mechanisms in order to overcome these threats of biotic and abiotic stresses. They sense the external stress environment, get stimulated and then generate appropriate cellular responses. They do this by stimuli received from the sensors located on the cell surface or cytoplasm and transferred to the transcriptional machinery situated in the nucleus, with the help of various signal transduction pathways. This leads to differential transcriptional changes making the plant tolerant against the stress. The signaling pathways act as a connecting link and play an important role between sensing the stress environment and generating an appropriate biochemical and physiological response.

Salt Stress in Plants and Amelioration Strategies: A Critical Review

“…The term stress in plants is defined as the environmental constraint that leads to the inhibition of morphological, physiological, and biochemical functioning of plants adversely affecting their growth and development [1][2][3][4]. The stresses may be biotic (pest, diseases, weed, etc.)…”

“…or abiotic (soil salinity, radiation, water lodging, drought, extreme temperature, organic and inorganic pollutants, etc.) [4][5][6][7][8][9][10][11][12] that may act alone or in combinations, limiting the productivity of crops and food security worldwide. Salt-affected soils (SAS) cause greatest environmental abiotic stresses to plants [13][14][15] and cover more than 20% of the cultivated lands throughout the world [16,17].…”

“…Salt-affected soils are grouped into saline, sodic, and saline-sodic and exhibit stresses to plants differently through various mechanisms. The principle mechanisms of salt stress in plants include osmotic effect, ionic toxicity, and nutritional imbalances [4,15]. The increase in the uptake of Na and Cl caused by the salt constraint is attributed to the reduction in N and P concentrations that may be due to the antagonistic relations of Na and Cl with ammonium (NH 4 + ), nitrate (NO 3 − ), and phosphate (H 2 PO 4 − ) [18,19].…”

Interactive Role of Silicon and Plant–Rhizobacteria Mitigating Abiotic Stresses: A New Approach for Sustainable Agriculture and Climate Change

“…The osmotic stress caused by abiotic factors disrupts ion distribution and cell homeostasis in plants. Abiotic stresses also interact with biotic stresses, making the plant more susceptible to infestations [ 7 , 8 ].…”

Diversity and Species Composition of Epiphytic Terrestrial Algae Exposed to Sulphur Dioxide Emissions Released From Power Plant Station

“…Short duration exposure of ISBN -978-93-86878-33-5 21st PATTAYA International Conference on Agricultural, Environmental and Biological Sciences (PAEBS-19) Pattaya (Thailand) Dec. [9][10]2019 high concentrations of SO 2 produce acute injury in plants while long-term exposure of low concentrations caused chronic injury [4]. SO 2 can also modify the response of plants to other environmental stresses, both biotic and abiotic [5]. Since epiphytic terrestrial algae (ETA) is known as an excellent bio-indicator, this study is focussing on the effect of pollutant to the diversity of ETA exposed to prolonged SO2 emissions released from a power plant station.…”