A Role for Plant KASH Proteins in Regulating Stomatal Dynamics  . Issue 2 (25th November 2019)

• Record Type: Journal Article
• Authors: Biel, Alecia; Moser, Morgan; Meier, Iris
• Is Part Of: Plant physiology. Volume 182:Issue 2(2020)
• Page Start: 1100
• Page End: 1113
• Publication Date: 2019-11-25
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.19.01010
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Protein complexes at the nuclear envelope—known to connect the nucleus to the cytoskeleton—affect stomatal opening and closing in response to a variety of signals. Abstract: Stomatal movement, which regulates gas exchange in plants, is controlled by a variety of environmental factors, including biotic and abiotic stresses. The stress hormone abscisic acid (ABA) initiates a signaling cascade, which leads to increased H2 O2 and Ca 2+ levels and F-actin reorganization, but the mechanism of, and connection between, these events is unclear. SINE1, an outer nuclear envelope component of a plant Linker of Nucleoskeleton and Cytoskeleton complex, associates with F-actin and is, along with its putative paralog SINE2, expressed in guard cells. Here, we have determined that Arabidopsis ( Arabidopsis thaliana ) SINE1 and SINE2 play an important role in stomatal opening and closing. Loss of SINE1 or SINE2 results in ABA hyposensitivity and impaired stomatal dynamics but does not affect stomatal closure induced by the bacterial elicitor flg22. The ABA-induced stomatal closure phenotype is, in part, attributed to impairments in Ca 2+ and F-actin regulation. Together, the data suggest that SINE1 and SINE2 act downstream of ABA but upstream of Ca 2+ and F-actin. While there is a large degree of functional overlap between the two proteins, there are also critical differences. Our study makes an unanticipated connection between stomatal regulation and nuclear envelope-associated proteins, and adds two new players to the increasingly complex system of guard cell regulation.