The phytotoxin myrigalone a triggers a phased detoxification programme and inhibits Lepidium sativum seed germination via multiple mechanisms including interference with auxin homeostasis

Nakabayashi K., Walker M., Irwin D., Cohn J., Guida-English S.M., Garcia L., Pavlović I., Novák O., Tarkowská D., Strnad M., Pérez M., Seville A., Stock D., Leubner-Metzger G.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 23: 4618, 2022

Keywords: TP-binding cassette (ABC) transporter, PIN auxin efflux carrier, WRKY transcription factors, allelochemical and allelopathy, aquaporin-mediated water transport, auxin transport and homeostasis, cis-(+)-12-oxophytodienoic acid (OPDA) reductase, gibberellin metabolism, phytotoxin detoxification programme, seed germination
Abstract: Improving yield, nutritional value and tolerance to abiotic stress are major targets of current breeding and biotechnological approaches that aim at increasing crop production and ensuring food security. Metabolic engineering of carotenoids, the precursor of vitamin-A and plant hormones that regulate plant growth and response to adverse growth conditions, has been mainly focusing on provitamin A biofortification or the production of high-value carotenoids. Here, we show that the introduction of a single gene of the carotenoid biosynthetic pathway in different tomato cultivars induced profound metabolic alterations in carotenoid, apocarotenoid and phytohormones pathways. Alterations in isoprenoid- (abscisic acid, gibberellins, cytokinins) and non-isoprenoid (auxin and jasmonic acid) derived hormones together with enhanced xanthophyll content influenced biomass partitioning and abiotic stress tolerance (high light, salt, and drought), and it caused an up to 77% fruit yield increase and enhanced fruit's provitamin A content. In addition, metabolic and hormonal changes led to accumulation of key primary metabolites (e.g. osmoprotectants and antiaging agents) contributing with enhanced abiotic stress tolerance and fruit shelf life. Our findings pave the way for developing a new generation of crops that combine high productivity and increased nutritional value with the capability to cope with climate change-related environmental challenges.
DOI: 10.3390/ijms23094618 IEB authors: Ondřej Novák, Miroslav Strnad, Danuše Tarkowská