NADES Compounds Identified in Hypoxis hemerocallidea Corms during Dormancy

Motiki M Mofokeng; Gerhard Prinsloo; Hintsa T Araya; Stephen O Amoo; Christian P du Plooy; Phatu W Mashela

doi:10.3390/plants11182387

NADES Compounds Identified in Hypoxis hemerocallidea Corms during Dormancy

Plants (Basel). 2022 Sep 13;11(18):2387. doi: 10.3390/plants11182387.

Authors

Motiki M Mofokeng^{1

2}, Gerhard Prinsloo³, Hintsa T Araya¹, Stephen O Amoo^{1

4}, Christian P du Plooy¹, Phatu W Mashela²

Affiliations

¹ Agricultural Research Council-Vegetable, Industrial and Medicinal Plants (ARC-VIMP), Private Bag X293, Pretoria 0001, South Africa.
² Green Technologies Research Centre, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa.
³ Department of Agriculture and Animal Health, University of South Africa, Private Bag X6, Johannesburg 1710, South Africa.
⁴ Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auckland Park, Johannesburg 2006, South Africa.

Abstract

Soaking Hypoxis hemerocallidea corms in distilled water improved the propagation and development of cormlets, suggesting the potential leaching-out of inhibitory chemical compounds. To investigate the presence of inhibitory compounds, nuclear magnetic resonance (NMR) spectral data of the leachate from dormant H. hemerocallidea corms were obtained using a 600 MHz ¹H-NMR spectrometer. The ¹H-NMR analysis led to the identification of choline, succinate, propylene glycol, and lactose, as inhibitory compounds. These four chemical compounds are part of the "Natural Deep Eutectic Solvents" (NADES) that protect plant cells during stress periods, each of which has the potential to inhibit bud growth and development. These compounds are supposedly leached out of the corms during the first rain under natural conditions, possibly accompanied by changes in the ratios of dormancy-breaking phytohormones and inhibitory compounds, to release bud dormancy. The identified chemical compounds heralded a novel frontier in the vegetative propagation of H. hemerocallidea as a medicinal plant, and for its enhanced sustainable uses.

Keywords: NADES; choline; lactose; organic acids; propagation; propylene glycol; succinate; sugars.

Grants and funding

The Department of Science and Innovation (South Africa) and the National Research Foundation (Grant No: 119286) are acknowledged for funding the work.