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The heavy metal zinc (Zn) is known to be transmitted in the food chain; however, the effect of Zn stress on beans and herbivorous insects is largely unclear. This study aimed to investigate the resistance of broad bean plants to Zn stress and the consequent changes in their physiological and biochemical metabolism by simulating heavy metal pollution in soil. Simultaneously, the effects of aphid progeny treated with different Zn concentrations on the expression of carbohydrate and related genes were analyzed. The results showed that Zn had no effect on the germination rate of broad beans, but other effects mainly manifested as follows. (1) Chlorophyll content decreased. (2) The total soluble sugar and Zn content in stems and leaves increased with increasing Zn content. (3) The proline content first increased and then decreased with increasing Zn content. (4) The height of the seedlings indicates that low concentrations promote growth and high concentrations inhibit growth. In addition, only the first-generation fecundity decreased significantly when aphids fed on heavy metal broad beans. Continuous high Zn levels increase the trehalose content of aphid F1 and F2, while F3 decreases. These results can not only provide a theoretical basis for exploring the impact of soil heavy metal pollution on ecosystems but also preliminarily evaluate the possibility of broad beans as a means of pollution remediation. [ABSTRACT FROM AUTHOR]

Plants use various secondary chemicals in their chemical defense against herbivores. While botanical insecticides are crucial for reducing the reliance on chemical pesticides, the development of plant-derived insecticides remains limited. In this study, we fed Henosepilachna vigintioctopunctata with three different host plants (Solanum nigrum, Solanum tuberosum, and Physalis floridana) and observed that feeding on P. floridana led to changes in the body size and a significantly high mortality rate. Through transcriptome analysis, it was found that the trehalose metabolism pathway of H. vigintioctopunctata changed significantly under different host feeding conditions, especially since the expression level of the trehalase gene was extremely different. We subsequently identified eight transcripts of HvTREs and analyzed their evolution and structure. Among them, significant differences are observed in the relative expression levels of HvTRE1-5 in H. vigintioctopunctata after the fourth instar and were affected by different plant diets. Compared with the natural host S. nigrum, the larvae that fed on P. floridana significantly reduced the contents of trehalose, glucose and glycogen and significantly affected the trehalase activity. Knockdown of HvTRE1-5 by RNAi increased mortality at the H. vigintioctopunctata prepupation stage, suggesting that HvTRE1-5 is important for H. vigintioctopunctata pupation. This study provides new insights into developing of green control methods for H. vigintioctopunctata and offers a valuable example for understanding the interaction between host plants and herbivorous insects. [ABSTRACT FROM AUTHOR]

An experimental model was made to investigate the influence of force and acoustic excitation on the vibration and underwater sound radiation of the stiffened conical-cylindrical shell. Meanwhile, a coupled precise transfer matrix method and wave superposition method was also proposed to analyze vibro-acoustic responses of combined shells. To test accuracy of the present method, vibration and acoustic results of combined shells are firstly examined. As expected, results of present method are in excellent agreement with the ones in literature and model test. The experimental results show that free vibrations of the experimental test are consistent with the literature data and the present method's results. Forced vibration and acoustic test results are also well agreed with the numerical results from the coupled precise transfer matrix method/wave superposition method. The comparisons show that the coupled precise transfer matrix method/wave superposition method is reliable and credible to solve the vibro-acoustic response of combined shells. The analysis shows that the acoustic excitation is the key factor for radiated noise in low-frequency range. However, the radiated noise resulted from force excitation is dominant in mid-high frequency band. [ABSTRACT FROM AUTHOR]