Selenium treatment differentially affects sulfur metabolism in high and low glucosinolate producing cultivars of broccoli (Brassica oleracea L.)

• Published in: Plant physiology and biochemistry Vol. 121; pp. 176 - 186
• Main Authors: McKenzie, Marian J., Chen, Ronan K.Y., Leung, Susanna, Joshi, Srishti, Rippon, Paula E., Joyce, Nigel I., McManus, Michael T.
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.12.2017
• Subjects: APS kinase; ATP sulfurylase; Brassica - genetics; Brassica - metabolism; Broccoli; Glucosinolate content; Glucosinolates - biosynthesis; O-acetylserine(thiol) lyase; Plant Proteins - genetics; Plant Proteins - metabolism; Selenium - pharmacology; Selenium application; Sulfur - metabolism; GSL; OASTL; Selenium application; GI; Sulfur metabolism; O-acetylserine(thiol) lyase; ATP sulfurylase; ATPS; MGB; MeSeCys; SeMet; SeCys; PAPS; Broccoli; Glucosinolate content; APSK; GB; SMT; APS kinase; Cys; Met
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2017.10.027

The effect of selenium (Se) application on the sulfur (S)-rich glucosinolate (GSL)-containing plant, broccoli (Brassica oleracea L. var. italica) was examined with a view to producing germplasm with increased Se and GSL content for human health, and to understanding the influence of Se on the regulation of GSL production. Two cultivars differing in GSL content were compared. Increased Se application resulted in an increase in Se uptake in planta, but no significant change in total S or total GSL content in either cultivar. Also no significant change was observed in the activity of ATP sulfurylase (ATPS, EC 2.7.7.4) or O-acetylserine(thiol) lyase (OASTL, EC 2.5.1.47) with increased Se application. However, in the first investigation of APS kinase (APSK, EC 2.7.1.25) expression in response to Se fertilisation, an increase in transcript abundance of one variant of APS kinase 1 (BoAPSK1A) was observed in both cultivars, and an increase in BoAPSK2 transcript abundance was observed in the low GSL producing cultivar. A mechanism by which increased APSK transcription may provide a means of controlling the content of S-containing compounds, including GSLs, following Se uptake is proposed. •Se treatment influenced Se content but not total S in both high and low GSL producing broccoli cultivars.•Total GSL content differed between cultivars, but was not influenced by Se treatment.•APSK homologues were isolated and their gene expression analysed in broccoli for the first time.•Se treatment influenced transcript abundance of the APSK gene family in both high and low GSL producing broccoli cultivars.