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Soybean membrane preparations specifically bound I'4Cjmycolami-naran, a branched 6-1,3-glucan produced by Phytophthora sp. which elicits production of the phytoalexin glyceollin in soybean tissues. A Scatchard plot of the binding data disclosed the presence of a single affinity class of binding sites with a Kd value of 11.5 micromolar for the glucan. To assess the physiologic importance of mycolaminaran binding in phytoalexin elicitation, several derivatives of mycolaminaran were prepared. Reduced mycolaminaran had slightly greater elicitor activity and binding affinity than the native substance, while periodinated mycolaminaran was virtually devoid of either elicitor activity or binding capability. Phosphorylated mycolaminaran, on the other hand, gave values for both elicitor activity and membrane binding which were intermediate between the native and periodinated preparations. No other tested carbohydrates competed with the binding of ['4Cjmycolaminaran. Soybean membrane preparations contained #-1,3-endoglucanase activity that degraded mycolaminaran and reduced both its efficiency as a phytoalexin elicitor and its membrane binding at temperatures above 0°C.Once ["Cjmycolaminaran bound to membranes, however, it was not appreciably susceptible to glucanase attack and could not be displaced with excess unlabeled ligand. Taken collectively, the observations suggest that the membrane binding sites are mycolaminaran-specific receptors which are physiologically involved in the initiation of phytoalexin production in soybean cotyledons. Because the binding of mycolaminaran to membranes was abolished by heat and proteolytic enzymes, the receptor is probably a protein(s) or glycoprotein(s).Phytoalexins are low mol wt antibiotic compounds that are inducibly formed in higher plant tissues after infection by microorganisms and appear to be responsible for disease resistance (6,11). The accumulation of phytoalexins in plants can also be stimulated by certain molecules of pathogen origin, termed elicitors, and these have been used to study the molecular basis of phytoalexin production and the expression of disease resistance (18,19 One method to assess critically the possible presence of receptors on cell membranes is direct binding assays using a homogeneous labeled ligand and isolated membranes. This approach has not been previously used in elicitor studies, probably due to difficulty in obtaining homogeneous, labeled carbohydrate elicitors. Phytophthora spp., however, produce a well characterized intracellular glucan, called mycolaminaran, that elicits glyceollin production in soybean tissues (9) and is unique because of its high degree of homogeneity (15)(16)(17). Mycolaminaran is composed of a linear polymer of about 30 glucose residues in (B 1,3-linkages, with two branching units connected through C-3 and C-6. The exact location of branch points and average chain length of the branches are yet to be experimentally elucidated.

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In recent decades, high-resolution (HR) remote sensing images have shown considerable potential for providing detailed information for change detection. The traditional change detection methods based on HR remote sensing images mostly only detect a single land type or only the change range, and cannot simultaneously detect the change of all object types and pixel-level range changes in the area. To overcome this difficulty, we propose a new coarse-to-fine deep learning-based land-use change detection method. We independently created a new scene classification dataset called NS-55, and innovatively considered the adaptation relationship between the convolutional neural network (CNN) and the scene complexity by selecting the CNN that best fit the scene complexity. The CNN trained by NS-55 was used to detect the category of the scene, define the final category of the scene according to the majority voting method, and obtain the changed scene by comparison to obtain the so-called coarse change result. Then, we created a multi-scale threshold (MST) method, which is a new method for obtaining high-quality training samples. We used the high-quality samples selected by MST to train the deep belief network to obtain the pixel-level range change detection results. By mapping coarse scene changes to range changes, we could obtain fine multi-type land-use change detection results. Experiments were conducted on the Multi-temporal Scene Wuhan dataset and aerial images of a particular area of Dapeng New District, Shenzhen, where promising results were achieved by the proposed method. This demonstrates that the proposed method is practical, easy-to-implement, and the NS-55 dataset is physically justified. The proposed method has the potential to be applied in the large scale land use fine change detection problem and qualitative and quantitative research on land use/cover change based on HR remote sensing data.

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Abstract:The climate changed from warm-dry to warm-wet during the 1960s in northwest China. However, the effects of climate change on the response of radial growth from different age-class trees have been unclear. We assessed the age-effect radial growth responses in three age-classes (ml-old: ≥200 years, ml-middle: 100-200 years and ml-young: <100 years) of Schrenk spruce (Picea schrenkiana Fisch. et Mey.) in the eastern Tianshan Mountains. The primary conclusions were as follows: the developed chronologies of the three age-class trees contained significant climate information and exhibited high similarity as shown by calculating the statistical parameter characteristics and Gleichlaufigkeit index. The three age-class trees were consistent for annual variation trends of radial growth under climate change, showing similar fluctuations, tree-ring width chronology trends, time trends of cumulative radial growth, and basal area increment. In addition, the old and middle trees were found to be more sensitive to climate variability by analyzing Pearson correlations between radial growth from three age-class trees and climate factors. As a result, the drought caused by reduced total precipitation and higher mean temperature was a limiting factor of tree radial growth, and the trees with ages of up to 100 years were more suitable for studies on the growth-climate relationships. Thus, the studies on age-effect radial growth responses of Schrenk spruce can help not only in understanding the adaptive strategies of different-age trees to climate change, but also provide an accurate basis for climate reconstruction.

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