Project description:We identified the involvement of OsPSKR, a receptor like kinase in wound responses in rice. OsPSKR regulates balance between growth and defense responses by suppressing exaggerated defense responses and promoting growth responses.
Project description:Wound induced small-peptide mediated signalling cascade regulated by a receptor like kinase- OsLRR-RLK1 dictates growth vs defense decision in rice
Project description:Phytosulfokine (PSK) is a plant pentapeptide hormone that fulfills a wide range of functions. Although it has been frequently reported to function in the inverse regulation of growth and defence in response to (hemi)biotrophic pathogens, the mechanism involved remains largely unknown. Using tomato (Solanum lycopersicum) and Pseudomonas syringae pv. tomato (Pst) DC3000 pathogen as a system, we present compelling evidence that the tomato PSK receptor PSKR1 interacts with the calcium-dependent protein kinase CPK28, which phosphorylates the key enzyme of nitrogen assimilation glutamine synthetase GS2 at two sites (S334 and S360 sites). These post translational modifications uncouple the two PSK-induced effects on defence responses and on growth regulation, respectively. The discovery of these sites will inform breeding strategies designed to optimize the growth-defence balance. The concept that such peptide hormones can regulate plant growth and resistance in a compatible manner is attractive, not least because crop yields and fitness can be optimized simultaneously in global climate-change era.
Project description:Phytosulfokine (PSK) is a plant peptide hormone that contributes to plant signaling and induced various of effects, including growth, senescence, stress tolerant and defense responses. PSK is a pentapeptide with two tyrosine sulfated by tyrosylprotein sulfotransferase (TPST) enzyme. The sulfated PSK can bind to its cell surface receptors, but the transcriptional readouts remain largely unknown. Here, we treated tpst mutant that are unable to produce native sulfated PSK with synthetic active PSK to capture concentration-sensitive readouts of PSK signaling.
Project description:Phytosulfokine (PSK) is a plant peptide hormone that contributes to plant signaling and induced various of effects, including growth, senescence, stress tolerant and defense responses. PSK is a pentapeptide with two tyrosine sulfated by tyrosylprotein sulfotransferase (TPST) enzyme. The sulfated PSK can bind to its cell surface receptors, but the transcriptional readouts remain largely unknown. Here, we treated tpst mutant that are unable to produce native sulfated PSK with synthetic active PSK to capture time-series and tissue-specific readouts of PSK signaling.
Project description:Phytosulfokine-α (PSK-α), a sulfated pentapeptide hormone with the sequence YIYTQ, plays important roles in many aspects of plant growth and development. In this study, we identified a pair of putative precursor genes in soybean, GmPSKγ1 and -2, encoding a PSK-like peptide: PSK-γ. Similar to PSK-α in amino acid composition, the sequence of PSK-γ is YVYTQ, and the tyrosines undergo sulfonylation. Treatment of Arabidopsis seedlings with synthetic sulfated PSK-γ significantly enhanced root elongation, indicating that PSK-γ might be a functional analog of PSK-α. Expression pattern analysis revealed that the two GmPSKγ genes, especially GmPSKγ1, are primarily expressed in developing soybean seeds. Heterologous expression of GmPSKγ1 under the control of a seed-specific promoter markedly increased seed size and weight in Arabidopsis, and this promoting effect of PSK-γ on seed growth was further confirmed in transgenic tobacco constitutively expressing GmPSKγ1. Cytological analysis of transgenic Arabidopsis seeds revealed that PSK-γ promotes seed growth by inducing embryo cell expansion. In addition, transcriptome analysis of GmPSKγ1-expressing Arabidopsis seeds suggested that PSK-γ signaling may regulate cell wall loosening to promote cell expansion. Overall, our results shed light on the mechanism by which PSK-γ promotes seed growth, paving the way for the use of this new peptide for biotechnological improvement of crop seed/grain size and yield.
Project description:Cavin-3 is a tumor suppressor protein of unknown function. Using a combination of in vivo knockout and in vitro gain/loss of function approaches, we show that cavin-3 dictates the balance between ERK and Akt signaling. Loss of cavin-3 increases Akt signaling at the expense of ERK, while gain of cavin-3 increases ERK signaling at the expense Akt. Cavin-3 facilitates signal transduction to ERK by anchoring caveolae, a lipid-raft specialization that contains an ERK activation module, to the membrane skeleton of the plasma membrane. Loss of cavin-3 reduces the number of caveolae, thereby separating this ERK activation module from signaling receptors. Loss of cavin-3 promotes Akt signaling through suppression of EGR1 and PTEN. The in vitro consequences of the loss of cavin-3 include induction of Warburg metabolism (aerobic glycolysis), accelerated cell proliferation and resistance to apoptosis. The in vivo consequences of cavin-3 loss are increased lactate production and cachexia. 9 total samples, consisting of 3 cavin-3 siRNA groups (0 days, 3 days and 8 days) one set was untreated, one set was serum starved, one set was serum starved and then treated with EGF for 1 hr.