Damage of brown planthopper (BPH) Nilaparvata lugens and rice leaf folder (LF) Cnaphalocrocis medinalis in parent plants lead to distinct resistance in ratoon rice.

Herbivore-induced defense responses are often specific, whereas plants could induce distinct defense responses corresponding to infestation by different herbivorous insects. Brown plant hopper (BPH) Nilaparvata lugens, a phloem-feeding insect, and rice leaf folder (LF) Cnaphalocrocis medinalis, a chewing insect, are both specialist herbivores on rice. To characterize the distinct resistance primed by prior damage to these two specialist herbivores, we challenged rice plants with two herbivores during vegetative growth of parent plants and assessed plant resistance in subsequent ratoons. Here, we show that LF and BPH induce different suites of defense responses in parent rice plants, LF induced higher level of JA accumulation and OsAOS, OsCOI1 transcripts, while BPH induced higher accumulation of SA and OsPAL1 transcripts. Moreover, an apparent loss of LF resistance was observed in OsAOS, OsCOI1 RNAi lines. Ratoon plants generated from parents receiving prior LF infestation exhibited higher jasmonic acid (JA) levels and elevated levels of transcripts of defense-related genes associated with JA signaling, while ratoon generated from parents receiving prior BPH infestation exhibited higher salicylic acid (SA) levels and elevated levels of transcripts of defense-related genes associated with SA signaling. Moreover, previous LF infestation obviously elevated ratoons resistance to LF, while previous infestation by BPH led to enhanced resistance in ratoons to BPH. Pre-priming of ratoons defense to LF was significantly reduced in OsAOS and OsCOI1 RNAi plant, but silencing OsAOS and OsCOI1 did not attenuate ratoons resistance to BPH. These results suggest that infestation of two specialist herbivores with different feeding styles in parent crop led to distinct defense responses in subsequent rations, and the acquired resistance to LF in ratoons is associated with priming of jasmonic acid-dependent defense responses.

Seed priming with calcium chloride enhances wheat resistance against wheat aphid Schizaphis graminum Rondani.

BACKGROUND: Calcium is an essential macronutrient for plant growth. Although it has been shown that exogenous Ca application can increase plant resistance to abiotic stress, little is known about its potential to enhance plant tolerance to biotic stress. Here, we investigated whether pretreatment of wheat (Triticum aestivum L.) seeds with calcium chloride (CaCl2 ) improves plant resistance against wheat aphid (Schizaphis graminum Rondani). The developmental time, population size, feeding behavior of aphids on plants grown from CaCl2 - and water-pretreated seeds, and plant defense responses to aphid attack were investigated. RESULTS: Seed pretreatment with CaCl2 extended aphid development time and reduced aphid population size and feeding efficiency. In addition, the pretreatment significantly increased the concentration of Ca2+ in wheat leaves, and upregulated expression levels of TaCaM genes and callose synthase genes (TaGSL2, TaGSL8, TaGSL10, TaGSL12, TaGSL19, TaGSL22 and TaGSL23). Callose concentration in the leaves of plants grown from CaCl2 -pretreated seeds increased significantly upon aphid attack. Further, callose deposition was observed mainly in the phloem. CONCLUSION: These results suggest that seed pretreatment with CaCl2 primes the plant response against wheat aphid attack, leading to modulation of callose deposition in the phloem in response to aphid attack. © 2021 Society of Chemical Industry.

Binuclear Tridentate Hemilabile Copper(I) Catalysts for Utilization of CO2 into Oxazolidinones from Propargylic Amines.

Four binuclear tridentate copper(I) complexes were synthesized based on the trans effect of the hybrid ligands. The catalytic performance and behavior of the prepared copper(I) complexes were evaluated in the carboxylative cyclization of propargylic amines with CO2. The combined use of copper(I) complexes and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) provided a catalytic system for the synthesis of a wide range of oxazolidinones from various propargylic amines and CO2 under mild reaction conditions (room temperature-40 °C and 1 bar CO2). The key factor for the success of the protocol is the use of copper complexes possessing the quality of hemilabile properties between N-heterocyclic carbenes and nitrogen donors. NMR measurements, density functional theory (DFT) calculations, and previous reports for the coordination behavior of the nickel complexes support the existence of the trans effect between N-heterocyclic carbenes and nitrogen donors.

A Study of Strain-Driven Nucleation and Extension of Deformed Grain: Phase Field Crystal and Continuum Modeling.

The phase-field-crystal (PFC) method is used to investigate migration of grain boundary dislocation and dynamic of strain-driven nucleation and growth of deformed grain in two dimensions. The simulated results show that the deformed grain nucleates through forming a gap with higher strain energy between the two sub-grain boundaries (SGB) which is split from grain boundary (GB) under applied biaxial strain, and results in the formation of high-density ensembles of cooperative dislocation movement (CDM) that is capable of plastic flow localization (deformed band), which is related to the change of the crystal lattice orientation due to instability of the orientation. The deformed grain stores the strain energy through collective climbing of the dislocation, as well as changing the orientation of the original grain. The deformed grain growth (DGG) is such that the higher strain energy region extends to the lower strain energy region, and its area increase is proportional to the time square. The rule of the time square of the DGG can also be deduced by establishing the dynamic equation of the dislocation of the strain-driven SGB. The copper metal is taken as an example of the calculation, and the obtained result is a good agreement with that of the experiment.

Phase II trial of Loubo® (Lobaplatin) and pemetrexed for patients with metastatic breast cancer not responding to anthracycline or taxanes.

PURPOSE: This phase II study was undertaken to determine the efficacy and safety of Loubo® (Lobaplatin) in combination with pemetrexed in treating patients with metastatic breast cancer who failed to respond to anthracycline or taxanes. PATIENTS AND METHODS: Metastatic breast cancer cases who had previously received an anthracycline and a taxane in either adjuvant or metastatic settings, were enrolled. All patients were recruited from Jiangsu Cancer Hospital and Research Institute, and were treated with Loubo® (Lobaplatin) 35 mg/m2 (intravenous; on day 1) and pemetrexed 500 mg/m2 (intravenous; on day 1) every 21 days. Efficacy and side effects were evaluated after at least two cycles of chemotherapy. RESULTS: All eligible 19 patients completed at least 2 cycles of chemotherapy with pemetrexed and lobaplatin, and were evaluable. Overall, 3 (15.8%) patients achieved partial response, 11 (57.9%) stable disease, 5 (26.3%) progression of disease, with no complete remission. Response rate was 15.8%, disease control rate was 42.1%. The median survival time was 10.3 months. Neutrophil suppression occurred in 36.8% of patients who had grade 2 toxicity, and 26.3% had grade 3, 26.4% had grade 4. Thrombocytopenia was encountered as follows: 21.1% grade 2, 15.8% grade 3 and 5.5% grade 4. Incidences of anemia were 10.5% in grade 2, 5.3% grade 3 and 0% grade 4. Only 5.3% of patients required packed red blood cell transfusion. Grade 3 digestive tract toxicity occurred in 5.5% of patients. Other toxicities included elevated transaminase, oral mucositis and skin rashes. CONCLUSIONS: The regimen of lobaplatin and pemetrexed is modestly active in metastatic breast cancer patients who failed anthracycline or taxanes, and the toxicity profile suggesting that the doses of chemotherapy should be further modified.