Altered levels of AOX1a expression result in changes in metabolic pathways in Arabidopsis thaliana plants acclimated to low dose rates of ultraviolet B radiation

Role of mitochondrial alternative oxidase in the regulation of cellular homeostasis during development of photosynthetic function in greening leaves

“…Our previous study results confirmed the individual roles of different NPhPs in greening cells. NDA2 has a diurnal expression pattern (high expression after 1–2 h of light exposure, followed by a decrease) (Garmash et al, 2017), similar to NDA1 in Arabidopsis leaves (Michalecka et al, 2003; Elhafez et al, 2006; Yoshida & Noguchi, 2009; Garmash et al, 2020). The highest expression of another gene encoding the internal NDs in wheat, i.e.…”

“…There is abundant evidence from studies in mutants with altered AOX expression, especially AOX1a in Arabidopsis . The altered expression of AOX1a in Arabidopsis alters the transcriptome and results in substantially different stress responses (Amirsadeghi et al, 2006; Giraud et al, 2008; Watanabe et al, 2008; Wang & Vanlerberghe, 2013; Garmash et al, 2020). Over 7000 genes, encoding proteins involved in antioxidant and other functions, were significantly altered in AOX1a knockout Arabidopsis plants even under normal conditions (Giraud et al, 2008).…”

“…Stress‐induced co‐expression of AOX and genes of other NPhPs in plants, including A. thaliana , is often observed. This suggests that the presence of multiple members of the alternative respiratory components ensure response flexibility, enabling the regulation of plant response to various stresses (Clifton et al, 2005; Yoshida & Noguchi, 2009; Rasmusson et al, 2009; Grabelnych et al, 2014; Garmash et al, 2020, etc.). On the one hand, there is evidence of AOX1a ‐dependent expression of genes of other NPhPs (reviewed in Yoshida & Noguchi, 2009), on the other hand, it is indicated that AOX1a expression is unaffected by the silencing of, e.g.…”

“…This suggests the possibility that light‐induced NDB2 expression may be controlled by the redox state in the photosynthetic electron transport chain (Yoshida & Noguchi, 2009). It has also been shown that other respiratory components may compensate for the absence of functional AtAOX1a (Watanabe et al, 2008, 2010; Garmash et al, 2020), suggesting a modulating role for AOX1a in the function of the mETC, especially during oxidative challenge under stress conditions.…”

Alternative oxidase1a and 1d limit proline-dependent oxidative stress and aid salinity recovery in Arabidopsis

“…Both AOX1a and AOX1d demonstrate a clear pattern of elevated expression under a range stress conditions such as salinity (Van Aken et al, 2009, Feng et al, 2013 and low nitrogen stress (Watanabe et al, 2010) and also in response to chemical inhibition of mETC complexes, such as with antimycin A (Strodtkotter et al, 2009). Manipulation of AOX1a expression in Arabidopsis under diverse environmental treatments such as cold (Fiorani et al, 2005), drought (Giraud et al, 2008), high CO 2 concentrations (Gandin et al, 2012), high arsenic (Demircan et al, 2020) and ecologically relevant doses of UV-B (Garmash et al, 2020) have highlighted the potential of AOX1a to enable acclimation to unfavourable growth conditions. AOX1a expression is particularly strongly upregulated by chemical disruption of complex II and III, and has been linked to mitochondrial retrograde signalling (Sweetlove et al, 2002, Clifton et al, 2005, Schwarzländer et al, 2011, Umbach et al, 2012 and the alleviation of excess reducing power arising from impediments to normal mETC activity (Jiang et al, 2019).…”