Intra- and inter-plant variability of quinolizidine alkaloids in narrow-leaf lupin seeds, grown under different day/night cycles

Tawfeek Khedr; Ling-Ling Gao; Lars G Kamphuis; Angéla Juhász; Michelle L Colgrave

doi:10.1016/j.heliyon.2025.e42367

Intra- and inter-plant variability of quinolizidine alkaloids in narrow-leaf lupin seeds, grown under different day/night cycles

Heliyon. 2025 Jan 29;11(3):e42367. doi: 10.1016/j.heliyon.2025.e42367. eCollection 2025 Feb 15.

Authors

Tawfeek Khedr¹, Ling-Ling Gao², Lars G Kamphuis^{2

3}, Angéla Juhász¹, Michelle L Colgrave^{1

2}

Affiliations

¹ School of Science, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
² CSIRO Agriculture and Food, Underwood Avenue, Floreat, WA, 6014, Australia.
³ Centre for Crop and Disease Management, School of Molecular and Life Science, Curtin University, Bentley, WA, 6102, Australia.

Abstract

Inconsistent fluctuation of quinolizidine alkaloid (QA) content in lupin seeds is often observed, sometimes surpassing safe thresholds (>200 mg/kg) yet lacks a clear explanation. This study aimed to investigate the intra-plant variability of QA content in three narrow-leaf lupin genotypes: Tanjil, Quillinock, and P22660 using LC-MS/MS. QA levels in seeds from the same pods showed <30 % variation, while those from different pods in the same plant sometimes surpassed inter-plant variations (up to 94 %). The average measured QA concentrations under speed breeding conditions in Quillinock, Tanjil, and P22660 were 36, 103, and 27,000 mg/kg, respectively. The impact of longer daylight hours (16h day/8h night), a practice used in speed breeding, on QA content in the cultivar Tanjil was also studied. Longer daylight hours yielded elevated QA levels in Tanjil seeds (103 mg/kg) compared to those grown in a greenhouse (10-13h daylight, 32 mg/kg).

Keywords: Abiotic stress; Lupinus species; Secondary metabolites; Speed breeding.