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1. G-dimension over local homomorphisms with respect to a semi-dualizing complex

Creator:
Dejun, Wu
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Cohen factorization, Gorenstein dimension, Gorenstein homomorphism, and semi-dualizing complex
Language:
English
Description:
We study the G-dimension over local ring homomorphisms with respect to a semi-dualizing complex. Some results that track the behavior of Gorenstein properties over local ring homomorphisms under composition and decomposition are given. As an application, we characterize a dualizing complex for $R$ in terms of the finiteness of the G-dimension over local ring homomorphisms with respect to a semi-dualizing complex.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Resistance of spinach plants to seawater stress is correlated with higher activity of xanthophyll cycle and better maintenance of chlorophyll metabolism

Creator:
Sun, J., Jia, X. Y., Guo, S. R., Li, J., and Shu, S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, chlorophyll metabolism, photoinhibition, seawater, spinach, and xanthophyll cycle
Language:
Multiple languages
Description:
The relationship between the activity of xanthophyll cycle and chlorophyll (Chl) metabolism was investigated using two cultivars, Helan No. 3 (seawater-tolerant cultivar) and Yuanye (seawater-sensitive cultivar), of spinach (Spinacia oleracea L.) plants cultured in Hoagland's nutrient solution, with or without seawater (40%). The results showed that, in plants of two cultivars with seawater, the xanthophyll cycle seems to show a principal protection mechanism against photoinhibition under seawater stress. Furthermore, accumulation of reactive oxygen species (ROS) in chloroplasts of two cultivars was enhanced by seawater to lower the activity of porphobilinogen deaminase. Namely, the conversion of porphobilinogen into uroporphyrinogen III involved in Chl biosynthetic processes was inhibited by seawater. In Helan No. 3 spinach plants with seawater, higher activity of xanthophyll cycle in the leaves dissipated more excess light energy, which appeared to lower the levels of ROS in chloroplasts. As a consequence, the Chl biosynthesis in Helan No. 3 leaves with seawater showed only a weak inhibition and the activity of chlorophyllase (Chlase) was not affected by seawater stress. In contrast, a more pronounced accumulation of ROS in chloroplasts of Yuanye leaves, which possess lower xanthophyll cycle activity, severely inhibited Chl biosynthesis and remarkably enhanced the activity of Chlase, which aggravates the decomposition of Chl. These results suggest that higher activity of xanthophyll cycle in seawater-tolerant spinach plays a role in maintaining Chl metabolic processes, probably by decreasing the levels of ROS, when the plants are cultured in the nutrient solution with seawater (40%). and J. Sun ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public