Effects of Combined Abiotic Stresses Related to Climate Change on Root Growth in Crops

Abstract

Climate change is a major threat to crop productivity that negatively affects food security worldwide. Increase in global temperatures are usually accompanied by drought, flooding and changes in soil nutrients composition that dramatically reduced crop yields. Against the backdrop of climate change, human population increase and subsequent rise in food demand, finding new solutions for crop adaptation to environmental stresses is essential. The effects of single abiotic stress on crops have been widely studied, but in the field abiotic stresses tend to occur in combination rather than individually. Physiological, metabolic and molecular responses of crops to combined abiotic stresses seem to be significantly different to individual stresses. Although in recent years an increasing number of studies have addressed the effects of abiotic stress combinations, the information related to the root system response is still scarce. Roots are the underground organs that directly contact with the soil and sense many of these abiotic stresses. Understanding the effects of abiotic stress combinations in the root system would help to find new breeding tools to develop more resilient crops. This review will summarize the current knowledge regarding the effects of combined abiotic stress in the root system in crops. First, we will provide a general overview of root responses to particular abiotic stresses. Then, we will describe how these root responses are integrated when crops are challenged to the combination of different abiotic stress. We will focus on the main changes on root system architecture (RSA) and physiology influencing crop productivity and yield and convey the latest information on the key molecular, hormonal and genetic regulatory pathways underlying root responses to these combinatorial stresses. Finally, we will discuss possible directions for future research and the main challenges needed to be tackled to translate this knowledge into useful tools to enhance crop tolerance.

Brassica napus Roots Use Different Strategies to Respond to Warm Temperatures

“…This problem will increase even more in agricultural systems, in which increased temperatures are usually accompanied by complex and concomitant detrimental soil conditions, such as enhanced evapotranspiration and compaction of the soil, changes in nutrient composition and moisture, and soil salinization. Root systems will be required to respond to all these heterogeneous soil environments by producing a combination of root traits that ensure plant survival [ 87 ]. For example, the production of shallow roots is an effective strategy for a scarcity of water, but when this is accompanied by poor soil nutrient content, root growth and lateral root branching has to be redirected into deeper regions of the soil where these resources are more abundant [ 88 ].…”

Ethylene and Jasmonates Signaling Network Mediating Secondary Metabolites under Abiotic Stress

“…Thus, to ensure world food security, there is an urgent need to find sustainable solutions to improve adaptability and resilience of plants to changing climatic conditions without crop yield losses [ 5 ]. Although advances have been made to gain insights into the regulatory mechanisms underlying plants’ response to abiotic stress adaptation and tolerance, we are still far from fully understanding them [ 6 , 7 ].…”

Molecular Mechanisms and Strategies Contributing toward Abiotic Stress Tolerance in Plants

“…They also have improved fruit quality, shelf life, and plant architecture. Genetic engineering of plants also results in reduced postharvest losses, which improve productivity and yield [4]. Induction of the expression of stress-related TFs (MYC, bzip, DREB1A, DREB1B, DREB1C, CBF1, CBF2), stress-responsive genes, signaling pathway kinases (MAPK, CDPK, S6K, PIP5K) hormonal biosynthesis (ABA, ethylene), antioxidant and ROS scavenging mechanism (APX, GSH, GR, GST, SOD, flavonoids, carotenoids), regulatory proteins (HSPs, LEA, dehydrins, aquaporins, metallothioneins, phytochelatins) osmolytes, and compatible solutes (proline, sorbitol, mannitol, polyamines, amino acids, glycine betaine), transporters (NHX, HKT, HMAs) improve the crop performance under altered environmental conditions.…”