Berkowitz is a molecular geneticist on the cutting edge of plant biotechnology research. He is currently working on improving the cultivation of industrial hemp.
Areas of Expertise (8)
Brandeis University: PhD, Plant Physiology 1983
Texas Tech University: MS., Crop Physiology 1980
Cornell University: BS., Agronomy 1977
College of Agriculture and Natural Resources Research Excellence (professional)
Cook College Research Excellence Award (professional)
Johnson & Johnson Discovery Research Award (professional)
Ma W., & Berkowitz GA.
Ca(2+) elevation in the cytosol is an essential early event during pathogen response signaling cascades. However, the specific ion channels involved in Ca(2+) influx into plant cells, and how Ca(2+) signals are initiated and regulate downstream events during pathogen defense responses, are at present unclear. Plant cyclic nucleotide gated ion channels (CNGCs) provide a pathway for Ca(2+) conductance across the plasma membrane (PM) and facilitate cytosolic Ca(2+) elevation in response to pathogen signals. Recent studies indicate that the recognition of pathogens results in cyclic nucleotide production and the activation of CNGCs, which leads to downstream generation of pivotal signaling molecules (such as nitric oxide (NO)). Calmodulins (CaMs) and CaM-like proteins (CMLs) are also involved in this signaling, functioning as Ca(2+) sensors and mediating the synthesis of NO during the plant pathogen response signaling cascade. In this article, these and other pivotal signaling components downstream from the Ca(2+) signal, such as Ca(2+)-dependent protein kinases (CDPKs) and CaM-binding transcription activators (CAMTAs), are discussed in terms of their involvement in the pathogen response signal transduction cascade.
Wei Ma, Andries Smigel, Robin K. Walker, Wolfgang Moeder, Keiko Yoshioka, Gerald A. Berkowitz
Ca2+ and nitric oxide (NO) are essential components involved in plant senescence signaling cascades. In other signaling pathways, NO generation can be dependent on cytosolic Ca2+. The Arabidopsis (Arabidopsis thaliana) mutant dnd1 lacks a plasma membrane-localized cation channel (CNGC2).
Wei MaKeiko YoshiokaChris GehringGerald A. Berkowitz
Plant cyclic nucleotide-gated ion channels conduct Ca2+ across the plasma membrane (PM) and facilitate cytosolic Ca2+ elevation during pathogen response signaling cascades. Until recently, not much was known about the specific ion channels involved in Ca2+ influx into plant cells, or how Ca2+ signals are generated and impact on downstream events during pathogen resistance responses. Recent studies, involving the cyclic nucleotide gated ion channel (CNGC) family of proteins, have provided new information relevant to these two areas of plant biology and will be reviewed in this chapter. Current evidence points to specific proteins that synthesize cyclic nucleotides and that function as ligands to activate CNGCs. The role of these channels in Ca2+ conduction appears critical to the generation of the hypersensitive response to pathogens, an important defense mechanism that limits disease in plants. Signaling downstream from Ca2+ during biotic stress responses involves cytosolic Ca2+-binding proteins such as calmodulin.