Comparing Rooting Ability and Physiological Changes of Two Eucommia ulmoides Improved Varieties

Eucommia ulmoides (E. ulmoides) is a significant national strategic resource in China. It is a natural high quality rubber resource, with great development potential. We found large differences in rooting ability during adventitious root (AR) formation in two E. ulmoides improved varieties. Therefore, we used two improved varieties of E. ulmoides, ‘Huazhong 6’ (H6, with rooting rate 85.3%) and ‘Huazhong 8’ (H8, with rooting rate 22.5%) to explore the cutting rooting mechanism. In this study, we mainly determined the morphological development process of E. ulmoides cutting rooting, and compared the rooting-related indexes of the two improved varieties, and the changes in physiological indexes closely related to rooting, which include endogenous hormones, oxidases and nutrients in the phloem of the basal stem. The results showed that indole–3–acetic acid (IAA), zeatin riboside (ZR), IAA/ZR and indoleacetic acid oxidase (IAAO) were the key factors that caused big differences in rooting ability between the two E. ulmoides improved varieties. The increase in endogenous hormone IAA content and IAA/ZR value were necessary for the formation of AR. The increase in IAA content was beneficial to AR formation. The activity of IAAO was significantly negatively correlated with the rooting ability of the E. ulmoides cuttings. The high IAAO activity of the H8 cuttings led to the consumption of IAA. Although the content of IAA increased, the rooting conditions were not reached. The accumulation of nutrients before rooting also has an important effect on rooting; it is easy for cuttings to root when the carbon–nitrogen ratio (C/N) value is high. This research provides an improved understanding of the cellular and physiological underpinnings of the AR process in woody plants. In addition, it provides a theoretical basis and foundation for subsequent research on E. ulmoides cuttage technology.

Effect of Auxin on Weedy Rice Mesocotyl Cell Wall Oxidase

The seedling was developed on the dark condition by artificial climate chamber to determine the content of Auxin (IAA), activity of indoleacetic acid oxidase (IAO) and cell wall peroxidase (POD), mesocotyl length change and cell wall oxidase activity variation applied IAA. The study proves that endogenous hormone IAA content of long mesocotyl in weedy rice were much higher than that of short mesocotyl in Akimitsu. With the growth of mesocotyl elongation, endogenous IAA content showed cumulative effects. And then accumulation of IAA content reached up to maximum, when the Mesocotyl elongation stoped to grow. IAA might play a decisive role in the process of hypocotyl elongation. Reduction in the activity of IAO and POD accelerated the transformation from bound IAA to free IAA and promoted cell elongation and mesocotyl elongation.

Response of salt stressed barley seedlings to phenylurea

The effect of phenylurea with reported cytokinin-like activities on seed germination, seedling growth, activities of antioxidant enzymes, polyphenol, peroxidase, indoleacetic acid oxidase, and total phenolic compounds, flavonoids was investigated in stressed barley seedlings. The application of phenylurea decreases the activity of peroxidase, indoleacetic acid oxidase and increases the activity of polyphenol oxidase with decrease in total phenolic compounds and flavonoids and consequent increase in growth rate. Saline (NaCl) stress in barley seedlings causes an increase in total phenolic compounds, flavonoids and enhancement of peroxidase and indoleacetic acid oxidase activities and consequent decrease in growth rate. The adverse effect of salt stress on germination, antioxidant enzymes, phenolic compounds, flavonoids can partially be rectified by phenylurea.

Peroxidase associated with the root surface of Phaseolus vulgaris

The surface of bean roots demonstrates an intense peroxidase activity which was detected by hydrogen peroxide dependent formation of chromogen from chloronaphthol or dianisidine. Other peroxidase functions, oxidation of indoleacetic acid and NADPH, were catalysed by intact roots and were stimulated by Mn2+ and p-coumarate. Oxidation of NADPH involved superoxide anion [Formula: see text] and hydrogen peroxide formation. Molecular sizing chromatography of root washes demonstrated NADPH oxidase and peroxidase to be associated with higher weight components than indoleacetic acid oxidase. Root surface and root wash peroxidase displayed optimal activity between pH 7 and 8, whereas both sources of indoleacetic acid oxidase were more active at acidic pH. Native poly aery lamide gel electrophoresis of sterile root washes displayed two fast-moving anodic bands, whereas homogenates of the plant roots had several slower moving bands in addition.

Peroxidase, indoleacetic acid oxidase, and amylase activity in necrotic wheat hybrid and its parents

At the seedling stage, growth pattern and changes in the activity of enzymes were studied in "necrotic" hybrid of wheat (Triticum aestivum) and its parents HI 617 (female) and HD 2160 (male). Growth of the hybrid is less when compared with either parent in light as well as in dark. In dark the hybrid shows higher activity of amylase, peroxidase, and indoleacetic acid oxidase than either parent. In light, however, the activity of peroxidase and amylase is intermediate between the two parents in the axis and root and higher than the parents in the endosperm of the hybrid. It appears that light modulates gene activity of the hybrid and in light the male-parent gene is dominant.