The expression of dehydrin genes and the intensity of transpiration in drought-stressed maize plants

The stress reaction of maize plants was evaluated in relation to drought stress intensity and to growth stages by assessing the transpiration intensity and the expression of two dehydrin genes, DHN1 and DHN2. The maize plants were grown under four different watering conditions: well-watered (control), mild stress, moderate stress and high stress. The sap flow values were taken as an indicator of plant stress reactions at the transpiration level. A significant correlation between the average diurnal values of sap flow and the volumetric soil moisture appeared only for the moderate stress condition (R = 0.528) and for the high stress condition (R = 0.395). Significant increases in the expression of DHN1 and DHN2 (DHN1 = 105-fold and DHN2 = 103-fold) were observed primarily for the high stress condition compared to the control. Differences in the stress reactions at the DHN1 gene expression level were detected for all the experimental drought stress conditions. A relatively close relationship between the levels of expression of both genes and the values of the sap flow was observed during the initial stage of the stress (R = –0.895; R = –0.893). The severity of water stress and transpiration intensity significantly affected certain biometric and yield parameters of maize. Higher DHN genes expression at the ripening stage was related to lower grain and dry biomass yield. The results indicated that DHN gene expression assessment in maize and evaluation of the changes in transpiration expressed by the sap flow could be considered appropriate indicators of stress intensity while the DHN gene expression assessment appeared to be more sensitive than evaluation of the changes in transpiration, mainly in the initial phases of stress response

HPPD GENE EXPRESSION IN RELATION TO VITAMIN E CONTENT IN SPRING BARLEY

Abstract KOSAŘ, M., HOLKOVÁ, L., BŘEZINOVÁ BELCREDI, N., EHRENBERGEROVÁ, J.: HPPD gene expression in relation to vitamin E content in spring barley. Acta univ. agric. et silvic. Mendel. Brun., 2009, LVII, No. 4, pp. 13-18 The enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) has a very important role in the biosynthetic pathway of vitamin E. Its activity infl uences the fi nal level of tocols in plant tissues. Seven barley cultivars with diff erent vitamin E level were grown under control conditions and activity of HPPD gene was measured four, eight and twelve days a er pollination of ear tissues. It was found that activity of HPPD gene corresponded with vitamin E content detected in grains (r = 0.77*). The relationship between the gene activity for HPPD eight and twelve days a er pollination and vitamin E content was also confi rmed for analyzed cultivars grown in the fi eld conditions (r = 0.85*)

Erratum to: Estimation of Sintering Kinetics of Magnetite Pellet Using Optical Dilatometer

Authors have used a new way for measuring bulk volume based on the image (pixel) analysis named as Light Table Imaging (LTI), and subsequently bulk densities and porosities. Authors lately found that there was a slight error in calibrating the scale (known distance) to pixel measurement and understand the need to communicate the error and subsequent corrections.  Erratum in: Metallurgical and Materials Transactions B, vol. 47, iss. 1, p. 309–319, DOI: 10.1007/s11663-015-0505-9</p