Understanding the role of SABP2-interacting proteins (SIP) 428: an NAD+-Dependent Deacetylase Enzyme in Abiotic Stress Signaling of Nicotiana tabacum

Abiotic stresses like salinity, drought, and extreme temperature are constantly on the rise, posing a very high risk to global agricultural productivity and food security. Hence, understanding stress signaling pathways can help engineer plants that can better withstand stress in unfavorable conditions. The salicylic acid (SA) signaling pathway has been widely studied for its important role in mediating abiotic stress in plants. In tobacco plants, Salicylic Acid Binding Protein 2 (SABP2), a methyl esterase enzyme, catalyzes the conversion of methyl salicylate (MeSA) to SA, which triggers the defense response via the SA-mediated signaling pathway. SIP-428 (SABP2 Interacting Protein-428) is an NAD+ dependent SIR2-like (Silent Information Regulator) deacetylase enzyme that likely interacts with SABP2 during SA biosynthesis. In previous studies, SIP-428 has been shown to be a negative regulator of plant growth under abiotic stress (NaCl and mannitol in vivo). Reactive Oxygen Species (ROS) are oxidizing oxygen products that accumulate under stress conditions, and at high levels can be very harmful to plants. Antioxidant enzymes such as catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), and superoxide dismutase (SOD) are actively involved in lowering the ROS levels in the cell by combating the oxidative stress. The objective of this study was to analyze the regulatory functions of SIP-428 in ROS signaling of tobacco plants through the biochemical quantification of POD and CAT activities. We investigated the SIP-428 RNAi-silenced tobacco plants for the POD and CAT enzyme activities in Osmotic (Mannitol) and Salinity (NaCl) stressed plants. Our results showed that SIP-428 plays a significant role in modulating antioxidant enzymes in stressed plants. This study has improved our understanding of some regulatory roles of SIP428, and its application can be used to enhance stress tolerance via the use of synthetic biology

Understanding the Role of SABP2-interacting Protein (SIP) 428: an NAD+-Dependent Deacetylase Enzyme in Abiotic Stress Signaling of Nicotiana tabacum

Abiotic stresses are constantly rising and pose a very high risk to global agricultural productivity and food security. Some plants have evolved several innate pathways for defense against these stresses. Hence, understanding stress signaling pathways can help develop crop plants with higher stress tolerance. The salicylic acid-mediated signaling pathway is important in plants experiencing biotic and abiotic stresses. In previous studies, SABP2-Interacting Protein (SIP-428) has been shown to be a negative regular of plant growth under abiotic stress. This study aimed to investigate the roles of SIP-428 in the ROS signaling of tobacco plants. We investigated transgenic RNAi-silenced lines of SIP-428 and wild-type tobacco plants for the activities of guaiacol peroxidase and catalase enzymes in Mannitol and NaCl-stressed plants for 7 and 14 days. Our results showed that SIP-428 plays a significant role in ROS signaling in Mannitol and NaCl-stressed plants via the activities of guaiacol peroxidase