Atmospheric nitrogen dioxide gas is a plant vitalization signal to increase plant size and the contents of cell constituents

Abstract

Summary We report the unexpected novel finding that exogenously supplied atmospheric NO2 at an ambient concentration is a plant vitalization signal to double shoot size and the contents of cell constituents. When seedlings of Nicotiana plumbaginifolia were grown for 10 wk under natural light and irrigation with 10 mm KNO3 in air containing (+NO2 plants) or not containing (–NO2 plants) 15NO2 (150 ± 50 ppb), shoot biomass, total leaf area, and contents per shoot of carbon (C), nitrogen (N), sulphur (S), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), free amino acids and crude proteins were all approximately 2 times greater in +NO2 plants than in –NO2 plants. In mass spectrometric analysis of the 15N/14N ratio, it was found that NO2‐derived N (NO2‐N) comprised < 3% of total plant N, indicating that the contribution of NO2‐N to total N was very minor. It thus seems very likely that the primary role of NO2 is as a multifunctional signal to stimulate plant growth, nutrient uptake and metabolism.

Nitrogen dioxide is a positive regulator of plant growth

“…Besides the involvement of NO 2 in protein tyrosine nitration, an important posttranslational protein modification, 13 the metabolism of NO 2 in plants has also been reported. 1 Although more than half a dozen NO production pathways or routes 14 exist in plants, and many studies have reported on NO 2 emission by plants, in vivo biosynthetic pathways for NO 2 are largely unexplored, other than reports on the enzymatic production of NO 2 . 15 However, in vitro production of NO 2 via single-electron oxidations of nitrite by hemeproteins such as horseradish peroxidase and leukocyte peroxidases, Arabidopsis hemoglobins, and human hemo/myoglobins have been demonstrated (Shapiro 2005, 13 and references therein).…”

“…Atmospheric NO and NO 2 have long been recognized as either detrimental or beneficial for plant development. 1,2 However, the molecular mechanisms of action underlying the effects have remained elusive. The 2 nitrogen oxide species readily interconvert in vivo, 3 and in vitro, 4 which suggests that there are similarities in their effects on plants.…”

Light-triggered selective nitration of PsbO1 in isolated Arabidopsis thylakoid membranes is inhibited by photosynthetic electron transport inhibitors

“…[25][26][27] Nitrogen analyses of gaseous 15 NO 2 -fed Arabidopsis plants have indicated that the contribution of NO 2 to total plant nitrogen is minor (>5%), and that NO 2 may function as a signal rather than a nutrient. 27 We also reported that some NO 2 -derived nitrogen is converted into oxidized nitrogen compounds, such as nitro and nitroso compounds.…”

Genetic engineering of nitrite reductase gene improves uptake and assimilation of nitrogen dioxide by Rhaphiolepis umbellata (Thunb.) Makino

“…After washing the membrane two times in wash buffer, the immunopositive spots were visualized using a Western Blot Chemiluminescence Reagent Plus (NEN Life Science, MA, USA) and VersaDoc 5000 imaging system (Bio-Rad). (Takahashi et al 2005). Leaves were harvested from the upper (1st to 4th leaves from the shoot apex) and middle (5th to 8th leaves) part of each plant.…”