The Role of ROS Homeostasis in ABA-Induced Guard Cell Signaling

Abstract

The hormonal and environmental regulation of stomatal aperture is mediated by a complex signaling pathway found within the guard cells that surround stomata. Abscisic acid (ABA) induces stomatal closure in response to drought stress by binding to its guard cell localized receptor, initiating a signaling cascade that includes synthesis of reactive oxygen species (ROS). Genetic evidence in Arabidopsis indicates that ROS produced by plasma membrane respiratory burst oxidase homolog (RBOH) enzymes RBOHD and RBOHF modulate guard cell signaling and stomatal closure. However, ABAinduced ROS accumulates in many locations such as the cytoplasm, chloroplasts, nucleus, and endomembranes, some of which do not coincide with plasma membrane localized RBOHs. ABA-induced guard cell ROS accumulation has distinct spatial and temporal patterns that drive stomatal closure. Productive ROS signaling requires both rapid increases in ROS, as well as the ability of cells to prevent ROS from reaching damaging levels through synthesis of antioxidants, including flavonols. The relationship between locations of ROS accumulation and ABA signaling and the role of enzymatic and small molecule ROS scavengers in maintaining ROS homeostasis in guard cells are summarized in this review. Understanding the mechanisms of ROS production and homeostasis and the role of ROS in guard cell signaling can provide a better understanding of plant response to stress and could provide an avenue for the development of crop plants with increased stress tolerance.

Non-Thermal Plasma Treatment Influences Shoot Biomass, Flower Production and Nutrition of Gerbera Plants Depending on Substrate Composition and Fertigation Level

“…On the other hand, the same reduction in gaseous exchange may have limited CO 2 intake, thus causing an additional stress, in compost-grown plants. Indeed, stomatal closure is induced by ROS [ 37 , 38 ] that might accumulate under NTP treatment; future research in this regard will help to bring about a better understanding of NTP effects. A slight decrease in % DW was also reported in NTP-treated plants under a HF regime in both peat and compost, but it did not affect plant DW, highlighting a general effect of NTP on this parameter.…”

The FLA4-FEI Pathway: A Unique and Mysterious Signaling Module Related to Cell Wall Structure and Stress Signaling

“…ABA is known to maintain turgor pressure during salt and drought stress by regulating the biosynthesis of osmolytes [67] and also controls ROS in both a positive and negative fashion [68,69]. It is presently unknown how FLA4-FEI signaling regulates ABA metabolism.…”

Overexpression of Maize ZmMYB59 Gene Plays a Negative Regulatory Role in Seed Germination in Nicotiana tabacum and Oryza sativa

“…During germination, ROS was found to inhibit cell growth by regulating expression of 4EBP and S6K (Toshniwal et al, 2019). The accumulation of ROS could be induced by ABA in Arabidopsis (Postiglione and Muday, 2020). In Physcomitrella patens, ppabi1a/b double mutant, in which ABA signaling was constitutively active, exhibited server growth retardation (Komatsu et al, 2013).…”