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BackgroundLotus japonicus is a perennial herb in Leguminosae. It is a good feed source and improves soil. It is also an excellent honey source and medicinal plant. Low-phosphorus and drought stresses are among the main abiotic stress factors limiting the production of pulse roots. MethodsIn this experiment, the effects of low-phosphorus and drought stresses on Baimai roots were analyzed under three treatments: control (zl1), low-phosphorus stress (zl2) and drought stress (zl3). Results A total of 2176, 3026 and 2980 differentially expressed genes were screened in zl1 vs. zl2, zl1 vs. zl3 and zl2 vs. zl3, respectively. The differentially expressed genes were enriched in functions related to cells, membranes, ion binding, enzyme activity and resistance to low-phosphorus and drought stresses. The enriched KEGG pathways included the MAPK signaling pathway-plant, flavor biosynthesis, starch and sucrose metabolism and plant hormone signal transmission. In particular, a large number of differentially expressed genes were enriched in the response to plant hormone signal transmission pathways among different treatments, and gene expression changes were analyzed. In addition, the differentially expressed genes identified under drought stress and the phase response genes identified under osmotic stress were upregulated. Differential metabolites were mainly enriched in the important metabolic pathways of flavonoid biosynthesis, arginine and proline metabolism and starch and sucrose metabolism. Differentially expressed proteins were mainly enriched in GO terms related to cell, membrane, ion binding and enzyme activity functions, and the main enriched KEGG pathways included the ribosome, starch and sucrose metabolism and plant hormone signal transmission pathways. ConclusionIn conclusion, these results of transcriptome, metabolome and proteome sequencing are helpful for understanding the response mechanisms, gene changes, metabolite changes and protein changes in Baimai roots under low-phosphorus and drought stress conditions to lay a foundation for future research on Lotus japonicus.

In order to realize high-speed automatic detection of various button switches, this paper develops a dual horizontal switch detection system based on PLC and touch screen. The dual horizontal switch detection system takes PLC as the control center, and realizes the automatic detection of the on-off performance and lifetime experiments for various push button switches through electric actuators. At the same time, the touch screen is used as the human machine interface (HMI) to communicate with PLC and electric actuator in real time through RS485 field-bus. The HMI realizes real-time monitoring the reproduction state of detection system through 3D graphical simulation and effectively realizes centralized control of on-site detection, and greatly improves the detection efficiency and automation. Practice has proved that the system runs reliably and stably, and has strong anti-interference ability.

Livestock grazing is a traditional and major use of grassland in China subtropics. However, plant stoichiometry and how it was affected by grazing in these ecosystems have been poorly explored. Here, the responses in plant nutrition and stoichiometry as well as soil nutrition and stoichiometry under representative grazing intensities (i.e., moderate grazing and heavy grazing) compared with no-grazing were characterized, the drivers of plant stoichiometry were explored in a subtropical artificial grassland, SW China. Wilcoxon test showed that grazing intensity significantly changed the response of soil OC, TN, AN, AP, AK, pH, OC: TN, AN: AP, AN: AK, AP: AK, and AP: AK. Grazing intensity changed the response in N, ASH, EE, ADF, P, N: P, N: P, N: Ca and P: Ca of plant. Path analysis showed the effect of grazing intensity on the stoichiometric ratio of nitrogen and phosphorus in plant community was achieved through the removal of herbivores. Our research provides some mechanistic understanding of grazing management of subtropical grassland, and also provides new insights and useful reference for the protection and utilization of grassland in Guizhou Plateau.