Submergence and drought are major constraints to rice (Oryza sativa) production in rain-fed farmlands, both of which can occur sequentially during a single crop cycle. SUB1A, an ERF transcription factor found in limited rice accessions, dampens ethylene production and gibberellic acid responsiveness during submergence, economizing carbohydrate reserves and significantly prolonging endurance. Here, we evaluated the functional role of SUB1A in acclimation to dehydration. Comparative analysis of genotypes with and without SUB1A revealed that SUB1A enhanced recovery from drought at the vegetative stage through reduction of leaf water loss and lipid peroxidation and increased expression of genes associated with acclimation to dehydration. Overexpression of SUB1A augmented ABA responsiveness, thereby activating stressinducible gene expression. Paradoxically, vegetative tissue undergoes dehydration upon desubmergence even though the soil contains sufficient water, indicating that leaf desiccation occurs in the natural progression of a flooding event.Desubmergence caused the upregulation of gene transcripts associated with acclimation to dehydration, with higher induction in SUB1A genotypes. SUB1A also restrained accumulation of reactive oxygen species (ROS) in aerial tissue during drought and desubmergence. Consistently, SUB1A increased the abundance of transcripts encoding ROS scavenging enzymes, resulting in enhanced tolerance to oxidative stress. Therefore, in addition to providing robust submergence tolerance, SUB1A improves survival of rapid dehydration following desubmergence and water deficit during drought.
Flooding is detrimental for nearly all higher plants, including crops. The compound stress elicited by slow gas exchange and low light levels under water is responsible for both a carbon and an energy crisis ultimately leading to plant death. The endogenous concentrations of four gaseous compounds, oxygen, carbon dioxide, ethylene, and nitric oxide, change during the submergence of plant organs in water. These gases play a pivotal role in signal transduction cascades, leading to adaptive processes such as metabolic adjustments and anatomical features. Of these gases, ethylene is seen as the most consistent, pervasive, and reliable signal of early flooding stress, most likely in tight interaction with the other gases. The production of reactive oxygen species (ROS) in plant cells during flooding and directly after subsidence, during which the plant is confronted with high light and oxygen levels, is characteristic for this abiotic stress. Low, well-controlled levels of ROS are essential for adaptive signaling pathways, in interaction with the other gaseous flooding signals. On the other hand, excessive uncontrolled bursts of ROS can be highly damaging for plants. Therefore, a fine-tuned balance is important, with a major role for ROS production and scavenging. Our understanding of the temporal dynamics of the four gases and ROS is basal, whereas it is likely that they form a signature readout of prevailing flooding conditions and subsequent adaptive responses.
Emerging data have indicated that hepatitis C virus (HCV) subverts the host antiviral response to ensure its persistence. We previously demonstrated that HCV protein expression suppresses type I interferon (IFN) signaling by leading to the reduction of phosphorylated STAT1 (P-STAT1). We also demonstrated that HCV core protein directly bound to STAT1. However, the detailed mechanisms by which HCV core protein impacts IFN signaling components have not been fully clarified. In this report, we show that the STAT1 interaction domain resides in the N-terminal portion of HCV core (amino acids [aa] 1 to 23). This domain is also required to produce P-STAT1 reduction and inhibit IFN signaling transduction. Conversely, the C-terminal region of STAT1, specifically the SH2 domain (aa 577 to 684), is required for the interaction of HCV core with STAT1. The STAT1 SH2 domain is critical for STAT1 hetero-or homodimerization. We propose a model by which the binding of HCV core to STAT1 results in decreased P-STAT, blocked STAT1 heterodimerization to STAT2, and, therefore, reduced IFN-stimulated gene factor-3 binding to DNA and disrupted IFN-stimulated gene transcription. Hepatitis C virus (HCV)is an enveloped, single-stranded RNA virus member of the family Flaviviridae. Its 9.6-kb genome includes a 5Ј untranslated region that acts as an internal ribosome entry site (IRES). The IRES directs the translation of a single open reading frame encoding the 3,010-amino-acid polyprotein, which is posttranslationally cleaved by host and virus-encoded protease into mature structural and nonstructural proteins (1, 14). The structural proteins include core, which forms the HCV viral nucleocapsid, and two envelope glycoproteins, E1 and E2 (31). The HCV structural proteins are cleaved and further processed to generate the mature and stable form of p21 HCV core (amino acids 1 to 191) (43). The nonstructural proteins NS2 through NS5 support viral RNA replication. For example, the NS3/4A protease catalyzes the posttranslational processing of nonstructural proteins from the viral polyprotein. NS5B encodes the HCV-encoded RNA-dependent RNA polymerase that is critical for HCV RNA replication. The HCV core protein has been found to be primarily located within the membranes of cytoplasmic organelles. The C terminus of HCV core is hydrophobic, while the N-terminal domain of HCV core is basic (33).HCV infection causes the development of chronic hepatitis and progression to liver cirrhosis and hepatocellular carcinoma. More than 170 million people are infected with HCV worldwide. Alpha interferon (IFN-␣) alone or in combination with ribavirin is the only currently approved treatment for HCV infection (9). Unfortunately, in many genotype 1 HCVinfected patients, HCV is refractory to the action of interferon (15). The precise mechanisms for HCV persistence are still not fully understood (21); thus, a more detailed understanding of virus-host interactions is critical.Viral infection stimulates the host type I IFN pathway. Following binding of secreted IFN to t...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.