A Formate Dehydrogenase Confers Tolerance to Aluminum and Low pH

Abstract

Formate dehydrogenase (FDH) is involved in various higher plant abiotic stress responses. Here, we investigated the role of rice bean (Vigna umbellata) VuFDH in Al and low pH (H + ) tolerance. Screening of various potential substrates for the VuFDH protein demonstrated that it functions as a formate dehydrogenase. Quantitative reverse transcription-PCR and histochemical analysis showed that the expression of VuFDH is induced in rice bean root tips by Al or H + stresses. Fluorescence microscopic observation of VuFDH-GFP in transgenic Arabidopsis plants indicated that VuFDH is localized in the mitochondria. Accumulation of formate is induced by Al and H + stress in rice bean root tips, and exogenous application of formate increases internal formate content that results in the inhibition of root elongation and induction of VuFDH expression, suggesting that formate accumulation is involved in both H + -and Al-induced root growth inhibition. Over-expression of VuFDH in tobacco (Nicotiana tabacum) results in decreased sensitivity to Al and H + stress due to less production of formate in the transgenic tobacco lines under Al and H + stresses. Moreover, NtMATE and NtALS3 expression showed no changes versus wild type in these over-expression lines, suggesting that herein known Al-resistant mechanisms are not involved. Thus, the increased Al tolerance of VuFDH over-expression lines is likely attributable to their decreased Al-induced formate production. Taken together, our findings advance understanding of higher plant Al toxicity mechanisms, and suggest a possible new route toward the improvement of plant performance in acidic soils, where Al toxicity and H + stress coexist.

An Oxalyl-CoA Synthetase Is Involved in Oxalate Degradation and Aluminum Tolerance

“…In fact, the expression pattern of VuFDH and VuAAE3 also differed in response to other metals ( Fig. 4; Lou et al, 2016). These results suggest that while oxalyl-CoA synthetase pathway is conserved for Al tolerance mechanism in plants, it may be not essential for other abiotic stresses.…”

“…4; Lou et al, 2016). In fact, the expression pattern of VuFDH and VuAAE3 also differed in response to other metals ( Fig.…”

“…Previously, we have found that several Al-responsive genes, e.g. VuSTOP1, VuMATE1, and VuFDH are also responsive to low pH regulation (Fan et al, 2014;2015;Lou et al, 2016). In order to examine whether expression of VuAAE3 is also sensitive to low pH, we investigated the effect of low pH stress on VuAAE3 expression.…”

Maize Oxalyl-CoA Decarboxylase1 Degrades Oxalate and Affects the Seed Metabolome and Nutritional Quality

“…This finding represented a breakthrough insight into oxalate metabolism in plants. The final step involved in formate catabolism catalyzed by formate dehydrogenase has also been reported (Suzuki et al, 1998;Lou et al, 2016b).…”

Characterization of the Soybean GmIREG Family Genes and the Function of GmIREG3 in Conferring Tolerance to Aluminum Stress

“…To investigate possible responses of GmIREGs to Fe deficiency, uniform seedlings were exposed to normal conditions (half-strength nutrient solution, pH 5.6) or low-iron conditions (half-strength nutrient solution without Fe-Na-EDTA, pH 5.6) for 14 days, during which time nutrient deficiency was observed [38]. For other treatments, uniform seedlings were exposed to a nutrient solution as previously described [39]; the nutrient solution contained 200 mM CaSO 4 , 200 mM CaCl 2 , 100 mM MgSO 4 , 400 mM KNO 3 , 300 mM NH 4 NO 3 , 5 mM NaH 2 PO 4 , 3 mM H 3 BO 3 , 0.5 mM MnCl 2 , 0.4 mM ZnSO 4 , 0.2 mM CuSO 4 , 10 mM Fe-EDTA, and 1 mM (NH 4 ) 6 Mo 7 O 24 . The solution was adjusted to pH 4.5 with HCl and renewed daily.…”