Wild and cultivated varieties of Camellia oleifera Abel. were studied for the response of their photosynthetic apparatus to Al toxicity and low-P stress in pot experiments with medium of acidic red soil. The effect was measured using physiological processes (growth, photosynthesis, chlorophyll a fluorescence), and pigment contents. The results showed that Al toxicity and low-P stress affected the seedlings' growth and leaves' photosynthesis, and the differences could be found between the two varieties. Lime plus P fertilizer treatment led to higher increase in the net photosynthetic rate (Pn) in the cultivar than in the wild variety. Pn increase was positively related to the increase of stomatal conductance (gs) and negatively correlated to intercellular CO 2 concentration (Ci) in both varieties. The maximum PSII quantum yield (Fv/Fm), the efficiency of excitation energy capture by open PSII reaction centers (Fv'/Fm'), the photochemical quenching (qP) and the efficiency of open PSII centers (U PSII ) significantly increased almost in all the treatment groups of both varieties, with the exception of an insignificant change in qP value for P 1 Al 1 group of cultivar. The insensitive qP and lower Pn for cultivar indicate a higher photosynthetic efficiency for the wild variety, though the U PSII was not significant between the two varieties. The pigment contents of oil tea seedlings under treatments changed significantly when lime and P were added, especially the Car/Chl ratio, suggesting carotenoid plays the role of photoprotection under high-Al and low-P stresses.Keywords Camellia oleifera Abel Á Acidic red soil Á Al toxicity Á P deficiency Á Photosynthesis Á Chlorophyll a fluorescence Abbreviations Al Aluminum P Phosphorus DW Dry weight Chl Chlorophyll Car Carotenoid Pn Net photosynthetic rate Ci Intracellular CO 2 concentration Gs Stomatal conductance PSII Photosystem II Fo, Fm, Fv Minimal, maximal and variable fluorescence yields Fm 0 , Fv 0 , Fs Maximal, variable and steady-state fluorescence yield in a light-adapted state Fv/Fm The maximal photochemical efficiency of PSII Fv 0 /Fm 0 The efficiency of excitation energy capture by open PSII reaction centre PPFD

The amorphous calcium carbonate (ACC) or polycrystalline vaterite, which has long-term water stability and thermal stability, can be induced by bacteria. These biogenic CaCO3 are organo-mineral complexes.

To explore the effect of Portulaca oleracea polysaccharides (POP) in regulating intestinal microflora in aged rats in vitro, its intestinal microbial composition was analyzed by 16 S rDNA high-throughput sequencing, and the level of short-chain fatty acids in fermentation broth was determined by LC-MS. POP significantly upregulated the relative abundance of Lactobacillus, Eggerthella, and Paraprevotella and significantly downregulated Escherichia_Shigella, Bacteroides, and Eubacterium nodatum groups. The pH value and ammonia nitrogen level decreased significantly in the POP-treated group, resulting in a more short-chain fatty acid consumption which changed the acid–base environment of the fermentation broth. In conclusion, POP is beneficial to aged rats because it can regulate intestinal flora, promote the growth of probiotics, and inhibit the reproduction of pathogenic bacteria.

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