Atmospheric nitric oxide stimulates plant growth and improves the quality of spinach (Spinacia oleracea)

Abstract

Nitric oxide (NO) is an endogenous signalling molecule implicated in a growing number of plant processes and has been recognised as a plant hormone. The present research employed spinach plant (Spinacia oleracea cv. Huangjia) and closed growth chambers to investigate the effects of gaseous NO application on vegetable production in greenhouses. Treatment of low concentration of NO gas (ambient atmosphere with 200 nL L 21 NO gas) significantly increased the shoot biomass of the soil-cultivated plants as compared with the control treatment (ambient atmosphere). In addition, the NO treatment also increased the photosynthetic rate of leaves, indicating that the enhancement of photosynthesis is an important reason leading to more biomass accumulation induced by NO gas. Furthermore, the NO treatment decreased nitrate concentration but increased the concentrations of soluble sugar, protein, antioxidants (vitamin C, glutathione and flavonoids), and ferric reducing-antioxidant power (FRAP) in shoots of the plants grown in soil, suggesting that the gaseous NO treatment can not only increase vegetable production but also improve vegetable quality. In addition, the effects of the combined application of NO and CO 2 (NO 200 nL L 21 and CO 2 800 lL L 21 ) on shoot biomass was even greater than the effects of elevated CO 2 (CO 2 800 lL L 21 ) or the NO treatment alone, implying that gaseous NO treatment can be used in CO 2 -elevated greenhouses as an effective strategy in improving vegetable production. Figure 4 Effects of NO and CO 2 gas treatments on concentrations of nitrate, soluble sugar and soluble protein in leaves of spinach (Spinacia oleracea L.). Seedlings at the first leaf stage were subjected to the following treatments: control (CO 2 350 lL L 21 ), NO (CO 2 350 lL L 21 and NO 200 nL L 21 ), CO 2 (CO 2 800 lL L 21 ) and CO 2 + NO (CO 2 800 lL L 21 and NO 200 nL L 21 ) in chambers. Plants were harvested and then nitrate, soluble sugar and soluble protein content were measured 20 days after treatments. Values represent the means AE standard errors (n = 3). An asterisk denotes significant difference from the control at P < 0.05. C.W. Jin et al.

Short‐term alteration of nitrogen supply prior to harvest affects quality in hydroponic‐cultivated spinach (Spinacia oleracea)

“…Carotene, ascorbic acid, glutathione, flavonoids and polyphenol serve as good oxidant scavengers, and these compounds are often used to assess antioxidant status and hence act as a parameter for vegetable quality . Here we observed that the carotene concentrations in the edible part of spinach plants from 6‐day NO 3 − ‐free treatments were lower than those from NO 3 − ‐containing treatments, indicating that the presence of NO 3 − in SANSPH should be a critical factor in maintaining the carotene level in plants.…”

“…Carotene, ascorbic acid, glutathione, flavonoids and polyphenol serve as good oxidant scavengers, 20,27 -29 and these compounds are often used to assess antioxidant status and hence act as a parameter for vegetable quality. 20,30 Here we observed that the carotene concentrations in the edible part of spinach plants from 6-day NO 3 − -free treatments were lower than those from NO 3 − -containing treatments, indicating that the presence of NO 3 − in SANSPH should be a critical factor in maintaining the carotene level in plants. However, both ascorbic acid and glutathione concentrations were increased with the elevation of NH 4 + concentration in the growth medium ( Table 3), indicating that NH 4 + facilitates the production of these compounds in plants.…”

Both the stimulation and inhibition of root hair growth induced by extracellular nucleotides in Arabidopsis are mediated by nitric oxide and reactive oxygen species

“…It can regulate plant growth in a dose-dependent fashion, with low concentrations promoting and high concentrations inhibiting growth (Anderson and Mansfield 1979;Hufton et al 1996;Leshem and Haramaty 1996;Gouvea et al 1997;Prado et al 2004;Lehner et al 2009;Jin et al 2009). In roots, NO stimulates tip growth and promotes root hair initiation (Yemets et al 2009).…”

Nitric Oxide Effects on Photosynthetic Rate, Growth, and Antioxidant Activity in Tomato

“…Nitric oxide acts as an antioxidant molecule and plays a protective role against stress (Beligni and Lamattina, 1999a) in a dose-dependent manner, the best being a concentration of 10 −5 M. The NR activity was stimulated by NO, possibly induced by a posttranslational regulatory pathway (Jin et al, 2009). The NR activity is enhanced by napthalene acetic acid (NAA) (an analogue of indole acetic acid (IAA)) in chicory (Cichorium intybus L.; Vuylsteker et al, 1998), by cytokinin benzyladenine in Arabidopsis (Yu et al, 2001), and by salicylic acid in maize (Zea mays L.; Jain and Srivastava, 1981).…”