Does GABA increase the efficiency of symbiotic N₂ fixation in legumes?

Figures & data

Figure 1 Simplified representations of the proposed metabolic routes of γ-aminobutyric acid (GABA) metabolism and the key enzymes involved in symbiotic nodules. Enzymes involved include: GabD, succinate semialdehyde dehydrogenase; GabT, GABA oxoglutarate aminotransferase; GDC, glutamate decarboxylase; GOGAT, glutamate oxoglutarate amidotransferase; GS, glutamine synthetase; N₂ase, nitrogenase; OpaA, omega amino acid pyruvate aminotransferase. Adapted from Prell et al.33

Table 1 Accumulation of γ-aminobutyric acid (GABA) in different organs of soybean under various environmental stresses

Stress/treatment	Organ/tissue	Reference
Water deficit	Nodules, xylem	Serraj, et al.15
Water logging	Xylem, root, nodules	Puiatti and Sodek41
Hypoxia (N2 exposure)	Leaves, nodules, root	Serraj, et al.15
Salt stress	Roots	Xing, et al.42
Cold stress	Leaves	Wallace, et al.43
Mechanical damage	Leaves	Wallace, et al.43
N stress	Xylem, root, nodules	Lima and Sodek44
	Xylem	Antunes, et al.45

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