Biology subjects

Revuru, B.

Publications and source records attributed to Revuru, B..

3 recordsLinked to original sources

bioRxiv2023

SmERF6 promotes the expression of terpenoid pathway in Salvia officinalis and improves the production of high value abietane diterpenes, carnosol and carnosic acid

Carnosol (CO) and carnosic acid (CA) are pharmaceutically important diterpenes predominantly produced in members of Lamiaceae, Salvia officinalis, Salvia fruticosa and Rosmarinus officinalis. Nevertheless, availability of these compounds in plant system is very low. With an effort to improve the in planta content of these diterpenes, SmERF6 (Salvia miltiorrhiza Ethylene Responsive Factor 6) transcription factor was expressed in S. officinalis heterologously. SmERF6 is known to bind at the promoter regions of Copalyl diphosphate synthase (CPS) and Kaurene synthase like (KSL) genes and improve ferruginol content, a common precursor for abietane diterpenes in Salvia genus. Transient expression of SmERF6 exhibited the inter-specific activity in promoting differential accumulation of diterpenes in S. officinalis. Overexpression studies showed elevation in the levels of CO (10-folds) and CA (8-folds). Further, in infiltrated leaves levels of ferruginol (50%) and CA derivatives (rosmanol, epirosmanal, methyl carnosic acid) were significantly upregulated along with the other signature terpenes. While, knockdown of homologous ERF6 resulted in drastic reduction of the metabolite content. Finally, stable transgenic lines of S. officinalis developed through in planta Agrobacterium mediated genetic transformation method accumulated higher levels of CO (4-folds) and CA (3-folds) as compared to wild plants. Overall, the present study is the first report on improving the content of pharmaceutically important diterpenes in S. officinalis by overexpressing pathway specific transcription factor. The current results showed convincing evidence for the concept of improving the content of specialized metabolite(s) in medicinal plants by manipulating the expression of key transcription factors.

plant biology↗

bioRxiv2021

ROS/RNS balancing, aerobic fermentation regulation and cell cycle control a complex early trait ('CoV-MAC-TED') for combating SARS-CoV-2-induced cell reprogramming

In a perspective entitled From plant survival under severe stress to anti-viral human defense we raised and justified the hypothesis that transcript level profiles of justified target genes established from in vitro somatic embryogenesis (SE) induction in plants as a reference compared to virus-induced profiles can identify differential virus signatures that link to harmful reprogramming. A standard profile of selected genes named ReprogVirus was proposed for in vitro-scanning of early virus-induced reprogramming in critical primary infected cells/tissues as target trait. For data collection, the ReprogVirus platform was initiated. This initiative aims to identify in a common effort across scientific boundaries critical virus footprints from diverse virus origins and variants as a basis for anti-viral strategy design. This approach is open for validation and extension. In the present study, we initiated validation by experimental transcriptome data available in public domain combined with advancing plant wet lab research. We compared plant-adapted transcriptomes according to RegroVirus complemented by alternative oxidase (AOX) genes during de novo programming under SE-inducing conditions with in vitro corona virus-induced transcriptome profiles. This approach enabled identifying a major complex trait for early de novo programming during SARS-CoV-2 infection, called CoV-MAC-TED. It consists of unbalanced ROS/RNS levels, which are connected to increased aerobic fermentation that links to alpha-tubulin-based cell restructuration and progression of cell cycle. We conclude that anti-viral/anti-SARS-CoV-2 strategies need to rigorously target CoV-MAC-TED in primary infected nose and mouth cells through prophylactic and very early therapeutic strategies. We also discuss potential strategies in the view of the beneficial role of AOX for resilient behavior in plants. Furthermore, following the general observation that ROS/RNS equilibration/redox homeostasis is of utmost importance at the very beginning of viral infection, we highlight that de-stressing disease and social handling should be seen as essential part of anti-viral/anti-SARS-CoV-2 strategies.

cell biology↗

bioRxiv2021

Adaptive reprogramming during early seed germination requires temporarily enhanced fermentation a critical role for alternative oxidase (AOX) regulation that concerns also microbiota effectiveness

Plants respond to environmental cues via adaptive cell reprogramming that can affect whole plant and ecosystem functionality. Microbiota constitutes part of plants inner and outer environment. This Umwelt underlies steady dynamics, due to complex local and global biotic and abiotic changes. Hence, adaptive plant holobiont responses are crucial for continuous metabolic adjustment at systems levels. Plants require oxygen-dependent respiration for energy-dependent adaptive morphology, such as, germination, root and shoot growth, formation of adventitious, clonal and reproductive organs, fruits and seeds. Fermentative paths can help in acclimation and, to our view the role of alternative oxidase (AOX) in coordinating complex metabolic and physiologic adjustments is underestimated. Cellular level of sucrose is an important sensor of environmental stress. We explored the role of exogenous sucrose and its interplay with AOX during early seed germination. We found that sucrose-dependent initiation of fermentation during the first 12 hours after imbibition (HAI) was beneficial to germination. However, parallel enhanced AOX expression was essential to control negative effects by prolonged sucrose treatment. Early down-regulated AOX activity until 12 HAI improved germination efficiency in the absence of sucrose, but suppressed early germination in its presence. Our results also suggest that seeds-inoculated arbuscular mycorrhizal fungi can buffer sucrose stress during germination to restore normal respiration more efficiently. Following this approach, we propose a simple method to identify organic seeds and low-cost on-farm perspectives for early selection on disease tolerance, predicting plant holobiont behavior and improving germination. Furthermore, our research strengthens the view that AOX can serve as powerful functional marker source for seed hologenomes.

cell biology↗