OBJECTIVE To study the effects of different concentrations of photosynthetic induction factor (PIF), methyl jasmonate (MeJA), ceric ammonium sulfate (ACS) and acetylsalicylic acid (ASA) on the accumulation of fucoxanthin in Phaeodactylum tricornutum, screen the best elicitor combination for fucoxanthin accumulation, and study the photosynthetic physiology and gene expression changes of fucoxanthin accumulation in Phaeodactylum tricornutum under the treatment of the best inducer combination. METHODS A four-factor, four-level orthogonal test was used to screen the best inducer combination to promote the accumulation of fucoxanthin in Phaeodactylum tricornutum, and the chlorophyll fluorescence parameters of Phaeodactylum tricornutum under the treatment of the best elicitor combination were detected by pulse-amplitude-modulation (PAM). The expressions of zds, lcyb, rbcL and psbA were detected by RT-qPCR. RESULTS The results of the orthogonal test showed that MeJA was the most significant factor affecting the accumulation of fucoxanthin in Phaeodactylum tricornutum cells, followed by ASA, and the best elicitor combination to promote the accumulation of fucoxanthin in Phaeodactylum tricornutum was 1 μg·L-1 PIF+0.2 mg·L-1 ACS+40 mg·L-1 ASA. The photosynthetic physiological study showed that the inductor treatment was able to increase the fucoxanthin content by 104% compared with the control group, which was 21.77 mg·g-1. The results of photosynthetic physiological study showed that the inducer combination significantly increased the rETRmax value (P<0.05) of Phaeodactylum tricornutum. The expression of rbcL gene was the highest, which was 2.0 times higher than that of the control treatment (P<0.01). CONCLUSION The expressions of rETRmax, chla content, lcyb, rbcL and psbA genes are highly significantly correlated with zds gene, and the photosynthetic efficiency can be improved by promoting the expression of photosynthetic genes and the relative electron transfer rate of PSⅡ, and the expression of genes related to the synthesis of lutein can promote the accumulation of fucoxanthin in Phaeodactylum tricornutum.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |