Poaceae vs. Abiotic Stress: Focus on Drought and Salt Stress, Recent Insights and Perspectives

Abstract

Poaceae represent the most important group of crops susceptible to abiotic stress. This large family of monocotyledonous plants, commonly known as grasses, counts several important cultivated species, namely wheat (Triticum aestivum), rice (Oryza sativa), maize (Zea mays), and barley (Hordeum vulgare). These crops, notably, show different behaviors under abiotic stress conditions: wheat and rice are considered sensitive, showing serious yield reduction upon water scarcity and soil salinity, while barley presents a natural drought and salt tolerance. During the green revolution (1940–1960), cereal breeding was very successful in developing high-yield crops varieties; however, these cultivars were maximized for highest yield under optimal conditions, and did not present suitable traits for tolerance under unfavorable conditions. The improvement of crop abiotic stress tolerance requires a deep knowledge of the phenomena underlying tolerance, to devise novel approaches and decipher the key components of agricultural production systems. Approaches to improve food production combining both enhanced water use efficiency (WUE) and acceptable yields are critical to create a sustainable agriculture in the future. This paper analyzes the latest results on abiotic stress tolerance in Poaceae. In particular, the focus will be directed toward various aspects of water deprivation and salinity response efficiency in Poaceae. Aspects related to cell wall metabolism will be covered, given the importance of the plant cell wall in sensing environmental constraints and in mediating a response; the role of silicon (Si), an important element for monocots' normal growth and development, will also be discussed, since it activates a broad-spectrum response to different exogenous stresses. Perspectives valorizing studies on landraces conclude the survey, as they help identify key traits for breeding purposes.

Plant Cell Walls Tackling Climate Change: Biotechnological Strategies to Improve Crop Adaptations and Photosynthesis in Response to Global Warming

“…The data of Landi and collaborators showed that in rice (O. sativa cv. Nipponbare) under drought stress at least two GH genes are activated in roots [177]. Noteworthy, an increase in UDP-Glc levels (the cellulose substrate) by overexpressing SuSy and UDP-glucose pyrophosphorylase (UGPase) encoding genes was shown to induce tolerance to water stress in concomitancy with enhanced cellulose accumulation [119].…”

Profiling of the Differential Abundance of Drought and Salt Stress-Responsive MicroRNAs Across Grass Crop and Genetic Model Plant Species

“…Within the Poaceae family of grasses for example, maize, wheat, and rice, are all deemed sensitive to reduced water availability or salinity, with each displaying severe yield reductions in response to either stress. However, barley (Hordeum vulgare L.), a closely related member within the Poaceae family, appears largely unaffected when exposed to either stress [131]. Moreover, it is common within abiotic responsive miRNA studies to profile the miRNA landscape of a "tolerant" versus a "sensitive" cultivar.…”

Physiological and Molecular Osmotic Stress Responses in Three Durum Wheat (Triticum Turgidum ssp Durum) Genotypes

“…Data showed a decrease in PEPC and increase in APX activities under osmotic stress; a slight decrease in GS activity was observed, together with an increase in G6PDH in all genotypes; GS and NRT2 expressions changed in a similar pattern in the different genotypes. Interestingly, Maali and YT13 showed higher transcript abundance for GDH under stress compared to ON66, suggesting the implication of GDH in protective phenomena upon osmotic stress.Agronomy 2019, 9, 550 2 of 15 the photosynthetic activity by its direct effect on CO 2 uptake, resulting in a significant reduction in biomass and shoot growth [2][3][4]. At the cellular level, water scarcity triggers a set of modifications in biological processes caused by modifications in gene expression [5].…”

“…Agronomy 2019, 9, 550 2 of 15 the photosynthetic activity by its direct effect on CO 2 uptake, resulting in a significant reduction in biomass and shoot growth [2][3][4]. At the cellular level, water scarcity triggers a set of modifications in biological processes caused by modifications in gene expression [5].…”