Brassinolide as potential rescue agent for Pinellia ternata grown under microplastic condition: Insights into their modulatory role on photosynthesis, redox homeostasis, and AsA-GSH cycling.

Microplastic (MP), as a new pollutant, not only affects the growth and development of plants but also may affect the secondary metabolites of plants. The anti-tumor role of Pinellia ternata is related to secondary metabolites. The role of brassinolide (BR) in regulating plant resistance is currently one of the research hotspots. The paper mainly explores the regulation of BR on growth and physiology of Pinellia ternata under MP stress. The experimental design includes two levels of MP (0, 1%) and two levels of BR (0, 0.1 mg/L). MP led to a marked reduction in plant height (15.0%), Fv/Fm (3.2%), SOD and APX activity (15.0%, 5.1%), whereas induced an evident raise in the rate of O2·- production (29.6%) and GSH content (4.4%), as well as flavonoids (6.8%), alkaloids (75%), and ß-sitosterol (26.5%) contents. Under MP addition, BR supply significantly increased plant height (15.7%), aboveground and underground biomass (16.1%, 10.3%), carotenoid and GSH content (11.8%, 4.2%), Fv/Fm (2.9%), and activities of SOD, GR, and MDHAR (32.2%, 21.08%, 20.9%). These results indicate that MP suppresses the growth of P. ternata, although it promotes secondary metabolism. BR can alleviate the inhibitory effect of MP on growth by improving photosynthesis, redox homeostasis, and the AsA-GSH cycle.

[Effects of Ca2+ on photosynthetic parameters of Pinellia ternata and accumulations of active components in heat stress].

OBJECTIVE: To study the effect of exogenous Ca2+ on photosynthetic parameters of Pinellia ternate and accumulations of active components under high temperature stress. METHOD: The pigment contents of P. ternata leaves, photosynthesis parameters and chlorophyll fluorescence parameters of P. ternata leaves, the contents of guanosine, adenosine and polysaccharide in P. ternata tubers were measured based on different concentrations of exogenous Ca2+ in heat stress when the plant height of P. ternata was around 10 cm. RESULT: The contents of total chlorophyll and ratio of chlorophyll a/b were relatively higher by spaying Ca2+. Compared with the control, spaying 6 mmol x L(-1) Ca2+ significantly enhanced the net photosynthetic rate (Pn), transpiration (Tr) and stomatal limitation (L8), but reduced intercellular CO2 concentration (C) in P. ternata leaves. With the increase of Ca2+ concentration, maximal PS II efficiency (Fv/Fm), actual photosynthetic efficiency (Yield) and photochemical quenching coefficient (qP) initially increased and then decreased, however, minimal fluorescence (Fo) and non-photochemical quenching coefficient (NPQ) went down first and then went up. The contents of guanosine and polysaccharide and dry weight of P. ternata tubers showed a tendency of increase after decrease, and the content of adenosine increased with the increase of Ca2+ concentration. The content of guanosine and polysaccharide in P. ternata tubers and its dry weight reached maximum when spaying 6 mmol x L(-1) Ca2+. CONCLUSION: With the treatment of calcium ion, the inhibition of photosynthesis and the damage of PS II system were relieved in heat stress, which increased the production of P. ternata tubers.

[Analysis of lipid compounds of high-yielded rhizoma pinelliae growing in the west of Hubei province by gas chromatography-mass spectrometry].

OBJECTIVE: To investigate lipid components of high-yielded Pinellia ternata rhizomes growing in the west of Hubei province. METHODS: To determine the lipid chemical components in Pinellia ternata rhizomes with GC-MS method and NIST atlas. RESULTS: Ten components have been found: palmitic acid (I), 9,12-octadecadienoic acid (II), pyrrolidine,1-(1-oxo-7,10-hexadecadienyl) (III), alpha-monpalmitin (IV), 1,3,12-nonadecatriene (V), campesterol (VI), stigmasta-5,22-dien-3-ol (VII), beta-sitosterol (VIII), stigmasta-5,24-dien-3-ol (IX), cycloartenol (X). CONCLUSION: The relative contents of five kinds of phytosterol: campesterol 28.96%, stigmasta-5,22-dien-3-ol 9.24%, beta-sitosterol 50.77%, stigmasta-5,24-dien-3-ol 4.74%, cycloartenol 6.25%. Component II, III, V, VI, IX are the first time reported in Pinellia ternata.