Search

Protein kinase CK2, which consists of two α and two β subunits, plays an essential role in plant development and is implicated in plant responses to abiotic stresses, including salt and heat. However, the function of CK2 in response to heavy metals such as cadmium (Cd) has not yet been established. In this study, the transgenic line CKB4ox , which overexpresses CKB4 encoding the CK2β subunit and has elevated CK2 activity, was used to investigate the potential role of CK2 in response to Cd stress in Arabidopsis thaliana . Under Cd stress, CKB4ox showed reduced root growth and biomass accumulation as well as decreased chlorophyll and proline contents compared with wild type. Furthermore, increased Cd accumulation and a higher H 2 O 2 content were found in CKB4ox , possibly contributing to the inhibition of CKB4ox growth under Cd stress. Additionally, altered levels of Cd and H 2 O 2 were found to be associated with decreased expression of genes involved in Cd efflux, Cd sequestration and H 2 O 2 scavenging. Taken together, these results suggest that elevated expression of CKB4 and increased CK2 activity enhance the sensitivity of plants to Cd stress by affecting Cd and H 2 O 2 accumulation, including the modulation of genes involved in Cd transport and H 2 O 2 scavenging. This study provides direct evidence for the involvement of plant CK2 in the response to Cd stress. [ABSTRACT FROM AUTHOR]

The isolation of secondary metabolites produced by plants can lead to the discovery of new insecticidal agents. The aim of this study was to identify secondary metabolites from the fruits of Carpesium abrotanoides , a well-known medicinal and poisonous plant belonging to the family Asteraceae, with the potential to act as natural insecticides. Two new sesquiterpene lactones 9β-hydroxy-1βH, 11αH-guaia-4,10(14)-dien-12,8α-olide ( 1 ) and 9β-hydroxy-1βH, 11βH-guaia-4,10(14)-dien-12,8α-olide ( 2 ) along with four known sesquiterpene lactones ( 3 - 6 ) and one monoterpenoid ( 7 ) have been isolated. The structures of these compounds were established on the basis of 1D and 2D NMR data and HRESIMS data interpretation. To characterize their insecticidal activities, bioassays were conducted using two insect pest species of agricultural importance. Compounds 1 – 7 showed antifeedant effects to 3rd instar larvae of Plutella xylostella (Lepidoptera: Plutellidae) in a concentration-dependant manner with EC 50 of 19.84, 42.82, 97.94, 96.90, 39.94, 37.35 and 43.99 mg/L, respectively. Moreover, all of these compounds display stomach-contact combination toxicity toward 4rd instar larvae of Bradysia odoriphaga Yang and Zhang (Diptera: Sciaridae) (LD 50 = 18.71, 80.29, 230.65, 319.67, 31.18, 40.87 and 68.47 mg/L, respectively). In general, this is the first report of insecticidal activities of secondary metabolites isolated from C. abrotanoides . Moreover, compound 1 showed the best insecticidal activity in the test, demonstrating its potential to be used as a natural insecticides. [ABSTRACT FROM AUTHOR]

Highlights • ETE of M. liliflora leaves (MLL) was rich in lignans and showed antioxidant activity. • 4 new lignans and 15 known lignans were isolated from ETE. • Lignans showed antioxidant, anti-inflammatory, antifungal and phytotoxic activities. • MLL were identified as a promising by-product for industrial applications. Abstract After harvesting the flower buds of Magnolia liliflora Desr. (the traditional Chinese medicine known as "Xinyi"), a significant quantity of M. liliflora leaf (MLL) was generated as a by-product. The aim of this study is to verify the potential use of MLL and isolate its bioactive compounds with antioxidant, anti-inflammatory, antifungal and phytotoxic activities. The ethyl acetate extract (ETE) from ethanol extract of MLL with the highest lignan content and antioxidant activity showed a good application value, from which four new lignans (1 – 4) along with fifteen known lignans (5 – 19) were isolated. The structures of lignans were established on the basis of 1D and 2D NMR data and HRESIMS data interpretation. Compounds 2 , 9 and 10 exhibited antioxidant activities as assessed by DPPH, ABTS and FRAP methods. Compounds 2–3 , 9–11 and 13–14 showed pronounced anti-inflammatory activities compared with positive control indomethacin. Compounds 9 , 11 and 19 showed antifungal effects on three plant pathogens of economic importance in agriculture (Fusarium graminearum , Pyricularia oryzae , Alternaria alternata) with MIC values ranging from 32 to 128 μg/mL. Compounds 5 and 11 showed an inhibitory effect on lettuce shoots with EC 50 = 0.37 and 0.95 mM, respectively. The results indicated that MLL could be regarded as a promising high-potential by-product and inexpensive source of lignans for the pharmaceutical, food and agricultural industries. [ABSTRACT FROM AUTHOR]