1.
Comparative proteomic analysis reveals that exogenous 6-benzyladenine (6-BA) improves the defense system activity of waterlogged summer maize.
Hu, J, Ren, B, Dong, S, Liu, P, Zhao, B, Zhang, J
BMC plant biology. 2020;(1):44
Abstract
BACKGROUND Exogenous 6-benzyladenine (6-BA) could improve leaf defense system activity. In order to better understand the regulation mechanism of exogenous 6-benzyladenine (6-BA) on waterlogged summer maize, three treatments including control (CK), waterlogging at the third leaf stage for 6 days (V3-6), and application of 100 mg dm- 3 6-BA after waterlogging for 6 days (V3-6-B), were employed using summer maize hybrid DengHai 605 (DH605) as the experimental material. We used a labeling liquid chromatography-based quantitative proteomics approach with tandem mass tags to determine the changes in leaf protein abundance level at the tasseling stage. RESULTS Waterlogging significantly hindered plant growth and decreased the activities of SOD, POD and CAT. In addition, the activity of LOX was significantly increased after waterlogging. As a result, the content of MDA and H2O2 was significantly increased which incurred serious damages on cell membrane and cellular metabolism of summer maize. And, the leaf emergence rate, plant height and grain yield were significantly decreased by waterlogging. However, application of 6-BA effectively mitigated these adverse effects induced by waterlogging. Compared with V3-6, SOD, POD and CAT activity of V3-6-B were increased by 6.9, 12.4, and 18.5%, LOX were decreased by 13.6%. As a consequence, the contents of MDA and H2O2 in V3-6-B were decreased by 22.1 and 17.2%, respectively, compared to that of V3-6. In addition, the leaf emergence rate, plant height and grain yield were significantly increased by application of 6-BA. Based on proteomics profiling, the proteins involved in protein metabolism, ROS scavenging and fatty acid metabolism were significantly regulated by 6-BA, which suggested that application of 6-BA exaggerated the defensive response of summer maize at proteomic level. CONCLUSIONS These results demonstrated that 6-BA had contrastive effects on waterlogged summer maize. By regulating key proteins related to ROS scavenging and fatty acid metabolism, 6-BA effectively increased the defense system activity of waterlogged summer maize, then balanced the protein metabolism and improved the plant physiological traits and grain yield.
2.
Association mapping for total polyphenol content, total flavonoid content and antioxidant activity in barley.
Han, Z, Zhang, J, Cai, S, Chen, X, Quan, X, Zhang, G
BMC genomics. 2018;(1):81
Abstract
BACKGROUND The interest has been increasing on the phenolic compounds in plants because of their nutritive function as food and the roles regulating plant growth. However, their underlying genetic mechanism in barley is still not clear. RESULTS A genome-wide association study (GWAS) was conducted for total phenolic content (TPC), total flavonoid content (FLC) and antioxidant activity (AOA) in 67 cultivated and 156 Tibetan wild barley genotypes. Most markers associated with phenolic content were different in cultivated and wild barleys. The markers bPb-0572 and bPb-4531 were identified as the major QTLs controlling phenolic compounds in Tibetan wild barley. Moreover, the marker bPb-4531 was co-located with the UDP- glycosyltransferase gene (HvUGT), which is a homolog to Arabidopsis UGTs and involved in biosynthesis of flavonoid glycosides . CONCLUSIONS GWAS is an efficient tool for exploring the genetic architecture of phenolic compounds in the cultivated and Tibetan wild barleys. The DArT markers applied in this study can be used in barley breeding for developing new barley cultivars with higher phenolics content. The candidate gene (HvUGT) provides a potential route for deep understanding of the molecular mechanism of flavonoid synthesis.
3.
Differentiation-inducing potency of the seco-steroid JK-1624F2-2 can be increased by combination with an antioxidant and a p38MAPK inhibitor which upregulates the JNK pathway.
Zhang, J, Posner, GH, Danilenko, M, Studzinski, GP
The Journal of steroid biochemistry and molecular biology. 2007;(1-5):140-9
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Abstract
Low calcemic analogs of vitamin D are candidates for differentiation therapy of human myeloid leukemias. We report here that the seco-steroid synthesized to have resistance to intracellular degradation and low calcemia-inducing activity, 1alpha-hydroxymethyl-3beta-16-ene-24,24-difluoro-25-hydroxy-vitamin D(3) (JKF), induces monocytic differentiation in four established human myeloid leukemia cell lines, HL60, U937, THP-1, NB-4, and murine myeloid leukemia cells WEHI-3B D(-). JKF has differentiation-inducing potency which is slightly lower than the physiologically active form of vitamin D, 1,25(OH)(2)vitamin D(3) (1,25D). However, simultaneous addition of carnosic acid (CA), an antioxidant, and SB20190 (SB), an inhibitor of p38MAP kinase, increases the differentiation efficiency of JKF to a level similar to the level observed when 1,25D is used in such combinations. We also show for the first time that SB inhibits the phosphorylation of MAPKAPK2, a downstream target of p38MAPK, but upregulates the phosphorylation of at least one of the isoforms of JNK (p46 JNK1) and of c-jun in all four human myeloid cell lines studied here. These studies indicate that the JNK1 pathway is positively associated with monocytic differentiation of several subtypes of myeloid leukemia cells arrested at different developmental stages. Further, since JKF is less calcemic than 1,25D, the data suggest that JKF combined with CA and SB is likely to have a therapeutic advantage over 1,25D-based experimental regimens for myeloid leukemias.