Table 2.

Comparison of the use of non-conventional pathways in developing embryos.

Species	Contribution of pNADP-ME to pPYR	Rubisco contribution to pPGA	Reversibility of IDH	Contribution to NADPH for FAS	References
Zea mays	30-54%	0%	No	74-76% OPPP 30-55% pNADP-ME	(Alonso et al., 2010; Cocuron et al., 2019)
Helianthus annuus	7%	0%	No	212% OPPP 6% pNADP-ME	(Alonso et al., 2007)
Glycine max	<20%	14%	Yes	<24% OPPP <29% pNADP-ME	(Allen et al., 2009)
Brassica napus	<1%	36-64%	Yes	25% OPPP <1% pNADP-ME	(Schwender et al., 2004; Schwender et al., 2006; Hay et al., 2014)
Thlaspi arvense	20%	25%	Yes	n.d.	(Tsogtbaatar et al., 2020)
Camelina sativa	9%	0%	Yes	6,079% OPPP 15% pNADP-ME	(Carey et al., 2020)
Linum usitatissinum	<1%	0%	Yes	186% OPPP <1% pNADP-ME	(Acket et al., 2019)

Published data from ¹³C-labeling and metabolic flux analysis obtained from developing embryos cultured under physiological conditions were used to determine the contribution of the plastidic NADP-dependent malic enzyme (pNADP-ME) to the production of plastidic pyruvate (pPYR); the contribution of Rubisco to plastidic phosphoglycerate (pPGA); the reversibility of the isocitrate dehydrogenase (IDH); and the contribution of the oxidative pentose-phosphate pathway (OPPP) and pNADP-ME to the production of NADPH necessary for fatty acid synthesis (FAS). Embryos from species highlighted in green are green embryos that may be photosynthetically active.