Anti-ABA polyclonal antibody

Stomatal pores play a central role in the control of carbon assimilation and plant water status. The guard cell pair that borders each pore integrates information from environmental and endogenous signals and accordingly swells or deflates, thereby increasing or decreasing the stomatal aperture. Prior research shows that there is a complex cellular network underlying this process. We have previously constructed a signal transduction network and a Boolean dynamic model describing stomatal closure in response to signals including the plant hormone abscisic acid (ABA), calcium or reactive oxygen species (ROS). Here, we improve the Boolean network model such that it captures the biologically expected response of the guard cell in the absence or following the removal of a closure-inducing signal such as ABA or external Ca2+. The expectation from the biological system is reversibility, i.e., the stomata should reopen after the closing signal is removed. We find that the model's reversibility is obstructed by the previously assumed persistent activity of four nodes. By introducing time-dependent Boolean functions for these nodes, the model recapitulates stomatal reopening following the removal of a signal. The previous version of the model predicts similar to 20% closure in the absence of any signal due to uncertainty regarding the initial conditions of multiple network nodes. We systematically test and adjust these initial conditions to find the minimally restrictive combinations that appropriately result in open stomata in the absence of a closure signal. We support these results by an analysis of the successive stabilization of feedback motifs in the network, illuminating the system's dynamic progression toward the open or closed stomata state. This analysis particularly highlights the role of cytosolic calcium oscillations in causing and maintaining stomatal closure. Overall, we illustrate the strength of the Boolean network modeling framework to efficiently capture cellular phenotypes as emergent outcomes of intracellular biological processes.

Mitogen-activated protein kinase kinase kinases (MAPKKKs or MEKKs) are crucial components of the MAPK signaling cascades, which play central roles in the signaling transduction pathways for plant growth, development, and response to abiotic stresses such as drought. The MAPKKK gene families in pepper have not been functionally characterized yet. Here, from the pepper genome, we predicted 27 putative MAPKKK genes belonging to the MEKK subfamily (namedCaMEKK1-27), based onin silicoanalysis. Phylogenetic analysis revealed that 14CaMEKKgenes were clustered into A5 of the five groups (A1-A5), of which 9 genes are primarily on chromosomes 2 and 7, and are located close to each other. These nine genes showed transcriptional regulation by treatment with abscisic acid (ABA) and drought stress in quantitative reverse-transcription PCR analysis. Among the ABA- and/or drought-inducedCaMEKKgenes, in a previous study, we isolatedCaAIMK1(Capsicum annuumABA Induced MAP Kinase 1), which plays a positive role in drought resistance via an ABA-dependent pathway. Our expression analysis and functional characterization of the MEKK subfamily genes will provide a better understanding of the functional roles of pepper MAPK cascades in ABA-mediated drought responses.