Beyond osmolytes and transcription factors: drought tolerance in plants via protective proteins and aquaporins

Abstract

Mechanisms of drought tolerance have been studied by numerous groups, and a broad range of molecules have been identified to play important roles. A noteworthy response of stressed plants is the accumulation of novel protective proteins, including heat-shock proteins (HSPs) and late embryogenesis abundant (LEA) proteins. Identification of gene regulatory networks of these protective proteins in plants will allow a wide application of biotechnology for enhancement of drought tolerance and adaptation. Similarly, aquaporins are involved in the regulation of water transport, particularly under abiotic stresses. The molecular and functional characterization of protective proteins and aquaporins has revealed the significance of their regulation in response to abiotic stresses. Herein, we highlight new findings regarding the action mechanisms of these proteins. Finally, this review also surveys the current advances in engineering drought tolerant plants, particularly the engineering of protective proteins (sHSPs and LEA) and aquaporins for imparting drought stress tolerance in plants.

Regulation of aquaporins in plants under stress

“…Different plant AQPs have different substrate specificities, localization, as well as transcriptional and posttranslational regulations [ 17 , 18 ]. Depending on membrane localization and amino acid sequence, AQPs in higher plants are classified into five subfamilies [ 19 ] including plasma membrane intrinsic proteins (PIPs), tonoplast intrinsic proteins (TIPs), nodulin-26 like intrinsic proteins (NIPs), small basic intrinsic proteins (SIPs), and X intrinsic proteins/uncharacterized-intrinsic proteins (XIPs) [ 20 – 22 ]. Plant species typically have a higher number of AQP genes than animals, ranging from 30 to 70 [ 4 , 18 , 23 ].…”

Physiological requirements for wheat ideotypes in response to drought threat

“…At the biochemical level, dehydration-tolerant plants are characterized by: (1) more effective identification and transduction of signals (including ABA) (Cutler et al 2010;Pantin et al 2013); (2) more efficient systems of protein repair or proteolytic removal (Grudkowska and Zagdańska 2004); (3) better protection of cell membranes by osmoprotectants (Iturriaga et al 2009;Zhang et al 2009); (4) the existence of LEA proteins (abundant late embryogenesis) interacting primarily with trehalose (Iturriaga 2008;Caramelo and Iusem 2009;Hussain et al 2011); (5) more stable photosynthesis (Jaleel et al 2009; Pinheiro and Chaves 2011); (6) more stable mitochondria metabolism (Atkin and Macherel 2009;Zagdańska, 1997); and (7) more stable tissue oxidation-reduction potential sustained by mechanisms inhibiting generation of free radicals as well as by their effective inactivation (Miller et al 2010).…”

Abiotic Stress Responses in Plants: Unraveling the Complexity of Genes and Networks to Survive

“…To cope with environmental stresses, plants activate a large set of genes, which lead to the accumulation of specific stress-associated proteins (reviewed in [253]). The stomatal limitation on photosynthesis imposed by the earlier stages of water deficit (WD) result in a decrease of primary electron acceptors available for photochemistry [47].…”