Abstract
Production of a volatile phenylpropene; eugenol in sweet basil is mostly associated with peltate glandular trichomes (PGTs) found aerially. Currently only one eugenol synthase (EGS), ObEGS1 which belongs to PIP family is identified from sweet basil PGTs. Reports of the presence of eugenol in roots led us to analyse other EGSs in roots. We screened for all the PIP family reductase transcripts from the RNA-Seq data. In vivo functional characterization of all the genes in E. coli showed their ability to produce eugenol and were termed as ObEGS2-8. Among all, ObEGS1 displayed highest expression in PGTs and ObEGS4 in roots. Further, eugenol was produced only in the roots of soil-grown plants, but not in roots of aseptically-grown plants. Interestingly, eugenol production could be induced in roots of aseptically-grown plants under elicitation suggesting that eugenol production might occur as a result of environmental cues in roots. The presence of ObEGS4 transcript and protein in aseptically-grown plants indicated towards post-translational modifications (PTMs) of ObEGS4. Bioinformatics analysis showed possibility of phosphorylation in ObEGS4 which was further confirmed by in vitro experiment. Our study reveals the presence of multiple eugenol synthases in sweet basil and provides new insights into their diversity and tissue specific regulation.
Highlights
Published: 12 January 2021Volatile organic compounds (VOCs) produced by plants as part of their secondary metabolism are critical to various biological processes, which includes defence mechanism, protection from ultraviolet irradiation, chemical signalling, plant-plant interactions and plant-environment interactions [1,2]
ObEGS1 was previously reported [19], whereas ObEGS2-8 which encoded 321, 309, 310, 315, 306, 308 and 306 amino acids respectively were newly identified in this study (Figure 2)
Fitness and adaption to the sionPlant levelssecondary of all ObEGSs were analysed in roots aseptically-grown plants and soilever-changing andObEGSs abiotic environment
Summary
Published: 12 January 2021Volatile organic compounds (VOCs) produced by plants as part of their secondary metabolism are critical to various biological processes, which includes defence mechanism, protection from ultraviolet irradiation, chemical signalling, plant-plant interactions and plant-environment interactions [1,2]. VOC emissions from plants can be constitutive or induced as a response to abiotic or biotic stresses [3,4,5,6,7]. It has been reported that accumulation of VOCs and expression of pathway genes in plants is organ- or tissue- specific or developmental stage specific [8,9]. A lot of progress with regards to elucidation of pathways leading to the formation of various plant VOCs has been made but information regarding the regulation of these specialized pathway especially under stress remains limited. Most of the studies on plant VOCs have focussed on emissions from aerial organs, but recent research shows that root produced VOCs play important and diverse roles in the rhizosphere. Root VOCs can affect microbial activity around it [10], alter behaviour of insects [11,12] and mediate belowground plant to plant communications [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
