Over-expression of the Arabidopsis formate dehydrogenase in chloroplasts enhances formaldehyde uptake and metabolism in transgenic tobacco leaves

Abstract

Over-expression of AtFDH controlled by the promoter of Rubisco small subunit in chloroplasts increases formaldehyde uptake and metabolism in tobacco leaves. Our previous study showed that formaldehyde (HCHO) uptake and resistance in tobacco are weaker than in Arabidopsis. Formate dehydrogenase in Arabidopsis (AtFDH) is a key enzyme in HCHO metabolism by oxidation of HCOOH to CO, which enters the Calvin cycle to be assimilated into glucose. HCHO metabolic mechanism in tobacco differs from that in Arabidopsis. In this study, AtFDH was over-expressed in the chloroplasts of transgenic tobacco using a light inducible promoter. C-NMR analysis showed that the carbon flux from HCHO metabolism was not introduced into the Calvin cycle to produce glucose in transgenic tobacco leaves. However, the over-expression of AtFDH significantly enhanced the HCHO metabolism in transgenic leaves. Consequently, the productions of [4-C]Asn, [3-C]Gln, [U-C]oxalate, and HCOOH were notably greater in transgenic leaves than in non-transformed leaves after treatment with HCHO. The increased stomatal conductance and aperture in transgenic leaves might be ascribed to the increased yield of oxalate in the guard cells with over-expressed AtFDH in chloroplasts. Accordingly, the transgenic plants exhibited a stronger capacity to absorb gaseous HCHO. Furthermore, the higher proline content in transgenic leaves compared with non-transformed leaves under HCHO stress might be attributable to the excess formate accumulation and Gln production. Consequently, the HCHO-induced oxidative stress was reduced in transgenic leaves.

A metabolomic strategy revealed the role of JA and SA balance in Clematis terniflora DC. Response to UVB radiation and dark

“…In a study of nitrogen metabolism under nitrate‐limited and dark conditions, Glu, Gln, Asp, Asn and Pro coincidently restored nitrogen content to wild‐type levels in a T‐DNA insertion mutant of Arabidopsis plastidial folylpolyglutamate synthetase gene (Meng et al ). The high Pro content in transgenic tobacco was also suggested to be attributable to excess Gln production (Wang et al , ). These results indicate that SA functions in nitrogen metabolism by enhancing metabolic flux from Glu, Gln and Asp to Pro, which results in an increased tolerance to oxidative stress by the accumulation of Pro in C. terniflora in response to HUVB + D.…”

“…In a study of nitrogen metabolism under nitrate-limited and dark conditions, Glu, Gln, Asp, Asn and Pro coincidently restored nitrogen content to wild-type levels in a T-DNA insertion mutant of Arabidopsis plastidial folylpolyglutamate synthetase gene (Meng et al 2017). The high Pro content in transgenic tobacco was also suggested to be attributable to excess Gln production (Wang et al 2017a(Wang et al , 2017b.…”

“…5B). GABA, a non-protein amino acid, plays an important protective role in plant stress resistance (Wang et al 2017a(Wang et al , 2017b. The GABA shunt pathway, which modulates the balance of the carbon-nitrogen ratio in plants, plays a major role in primary carbon metabolism (Fait et al 2008) and is functionally linked with the tricarboxylic acid cycle (TCA) (Studart-Guimarães et al 2007).…”

Dynamics of plant responses to combinations of air pollutants

“…; Wang et al . ). Moreover, we know that plant‐associated microbiomes take part in the biochemical process of phytoremediation.…”

Resistance to degradation of reserve proteins in beans after hydration and cooking

“…When consumed, it can exert anti-nutritional effects and cause toxicological manifestations, having a reduction in its concentration due to denaturation in cooked grains of P. vulgaris (Sun et al, 2019). On the other hand, the band of approximately 42 kDa can indicate the presence of the mitochondrial enzyme formate dehydrogenase (FDH), which takes part in important biosynthetic reactions and is considered as an universal stress marker protein, involved in responses to various types of abiotic and biotic stresses (McNeilly et al, 2018;Wang et al, 2018).…”