Soluble Sugars in Plants Under Stress at the Arabian Gulf Region: Possible Roles of Microorganisms

Abstract

This review discusses the functions of soluble sugars (as compatible solutes) in supporting the growth of plants under osmotic stress, and the perspectives of research on the role of the associated microorganisms as a new approach in providing these solutes to plants. Previous findings have suggested that plants sacrifice from their energy and reserves to build up compatible solutes and to perform various functions; as osmo-protectants and possibly to stabilize biomolecules, and to achieve osmotic adjustment between the plants and their environments. However, many reports have shown contradictory and controversial results, since there was no consistency in the response of plants to various types of abiotic stresses, during various stages of growth and development. Recent outcomes have revealed that other soluble sugars such as trehalose, might accumulate under extreme environmental conditions by various groups of microorganisms (bacteria and fungi), to support the growth of native plants and crops. This review reports the possibility of the presence of trehalose in the native plants of Qatar, as well as the associated microorganisms. However, articles in large numbers from around the world have shown no clear indication that this sugar accumulates in these plants, and no attempts have been made to measure it. More studies are concentrating on the perspectives of research, regarding the possible role of these soluble sugars that are synthesized in bacteria and fungi, to support the growth of plants in the Arabian Gulf region with a new look of innovative researches, to introduce traits using modern gene technology to build trehalose in some crops. The possible negative impact of the accumulation of compatible solutes in general and the soluble sugars in particular on plant metabolism and growth is discussed, presenting some evidences that have been raised during the last four decades and examples from higher plants.

Metabolic responses of wheat seedlings to osmotic stress induced by various osmolytes under iso-osmotic conditions

“…They serve as metabolic precursors for other metabolites or together with other metabolites, such as GABA or polyamines, may act as signalling molecules, controlling the gene expression in various metabolic pathways [25]. Yasseen et al [26] concluded that sugars can contribute to about 30–50% of the osmotic adjustment in the leaves of many glycophytes. In the present work, we found that sugar accumulation also depended on the nature of the osmotica.…”

Microbial Ecology of Qatar, the Arabian Gulf: Possible Roles of Microorganisms

“…Instead, most root exudates are of antimicrobial actions and might boost many activities related to growth under extreme environmental conditions (Huck et al, 1991;Walker et al, 2003;Srividya et al, 2008;Ahmed et al, 2013;Bizuye et al, 2013). Researchers should now conduct comprehensive investigations to explore the reality of the role of microbes at the rhizosphere, including contributions to resisting extreme biotic and abiotic factors (Glick, 2014;Hanin et al, 2016;Yasseen, 2018a,b, 2021;Yasseen et al, 2018).…”

“…During the last decade, great efforts have been made to draw attention to potential contributions of microorganisms to solving the many problems facing humans (Glick, 2012(Glick, , 2014Hanin et al, 2016;Al-Thani and Yasseen, 2018bYasseen et al, 2018). Moreover, some recent works [e.g., Egamberdievea et al (2017) and Yan et al (2020)] have suggested that rootassociated microbes offer some support to the growth of plants by producing phytohormones against abiotic stresses .…”

“…Moreover, in such desert and saline habitats under harsh environmental conditions, many flora, fauna, and microorganisms (Batanouny, 1981;Abulfatih et al, 2001;Abdel-Bari, 2012) play various biological roles. Those roles related to microbes have been attracting much interest (Al-Thani and Yasseen, 2018a;Al-Thani and Yasseen, 2020), and recent works suggested many possible activities that these microorganisms might play, such as contributing to energy equilibrium (Abulfatih et al, 2001;Al-Thani and Yasseen, 2018b;Yasseen et al, 2018). Recent publications have described the activities of microorganisms in the phytoremediation of polluted soils and waters Yasseen, 2020, 2021).…”