Transcriptome sequencing and screening of genes related to sex determination of Trichosanthes kirilowii Maxim

Trichosanthes kirilowii Maxim. (TK) is a dioecious plant in the Cucurbitaceae for which different sexes have separate medicinal uses. In order to study the genes related to sex determination, transcriptome sequencing was performed on flower buds of male and female plants using the high-throughput sequencing technology. A total of 145,975 unigenes and 7110 DEGs were obtained. There were 6776 DEGs annotated to 1234 GO terms and enriched to 18 functional groups, including five biological processes related to sugar metabolism. KEGG pathway analysis indicated genes involved in hormone transduction, hormone synthesis and carbohydrate metabolism. Many DEGs of TK are involved in reproductive organ formation, hormone signal transduction and regulatory networks. Combining the results of GO, KEGG and qRT-PCR, 11 sex determining candidate genes of TK were selected, including MYB80, MYB108, CER1, CBL9, ABCB19, SERK1, HSP81-3, ACS9, SEP3, AUX1 and YUC6. The results provide a foundation for the study of sex differentiation in TK.

[Effect of smoke water and distillation liquid on the seed germination and seedling growth of Trichosathes kirilowii]

Smoke water and distillation liquid were used to treat the seeds of Trichosathes kirilowii and to study the effects of smoke water and distillation liquid on the seed germination and seedling growth of T. kirilowii. The results showed that germination rate, germination index and germination vigor of T. kirilowii all were significantly improved with the treatment of SW and DL treatment. The activity of α-amylase were significantly increased with the treatment of SW and DL at 1:2,000. SW and DL treatment showed no significant effects on the activity of SOD. The activity of POD were markedly enhanced under the treatment of SW (1:000) and DL (1:2,000). CAT activity were increased with the treatment of SW and DL at 1:2,000 while were inhibited by SW and DL at 1:500. Seedling height and root length were increased with the treatment of SW and DL (1:1,000, 1:2,000). SW and DL treaments improved the content of chlorophyll, and moreover with the concentration of SW and DL, the stimulatory were also increased. This work demonstrated that smoke water and diatillation liquid at 1:2,000 could stimulate the seed germination and seedling growth of T. kirilowii, and it provided the references for the study of seed germination technology.

[Comparison on surface ultrastructure characteristic and drought resistance of different Trichosanthes kirilowii strains]

Trichosanthes kirilowii has been widely cultivated as its medicinal use, health care and food value. Drought resistance of seedlings is an important feature in breeding. Seeds of two T. kirilowii strains were used to research the difference of surface ultrastructure characteristic and drought resistance. Scanning electron microscope was used to identify the surface ultrastructure characteristic of seeds and PEG was used to simulate drought stress. The seeds germination rate, MDA content, chlorophyll content and the antioxidant enzymes activity were measured under the drought stress. The results showed that the seed surface colour of KXY-001 was lighter than that of KXY-005. The testa cobwebbing of KXY-001 was more intensive than that of KXY-005. The germination rate of KXY-001 was higher than that of KXY-005 under drought stress. The MDA content was increased and the chlorophyll content was decreased with the increasing of drought degree. The SOD activity of KXY-001 was higher than that of KXY-005, while the activity of POD and CAT was also increased firstly and decreased later. Surface reticulate of seeds and hilar traits can be used as identification points to identify the investigated strains. SOD and POD are activated to resist drought in T. kirilowii seedlings and the drought resistance of KXY-001 is superior than that of KXY-005.

[Influence of different processing methods and mature stages on 3,29-dibenzoyl rarounitriol of Trichosanthes kirilowii seeds]

OBJECTIVE

To study the different mature stages and the best processing methods on the quality of Trichosanthes kirilowii seeds.

METHODS

The content of 3,29-dibenzoyl rarounitriol in Trichosanthes kirilowii seeds was determined by HPLC. The sample of different mature stages such as immature, near mature and fully mature and processed by different methods were studied.

RESULTS

Fully mature Trichosanthes kirilowii seeds were better than the immatured, and the best processing method was dried under 60degrees C, the content of 3,29-dibenzoyl rarounitriol reached up to 131.63microlg/mL.

CONCLUSION

Different processing methods and different mature stages had a significant influence on the quality of Trichosanthes kirilowii seeds.

[Dynamic analysis of mineral elements during growth and development stage of the Kirilowii plant]

ICP-AES technology was used to determine the major mineral elements content and analyze the dynamic and cumulative amount of the main absorption during the growth and development stage of the Kinlowii organs plant. The result showed as follows: (1)The mineral elements were changing in the different stage. The highest mineral element accumulation of K, P, Ca, Mg, Fe, Mn, Zn, Cu and Mo occured in October, their values are 3,695.90, 445.88, 9,649.32, 2,652.10 mg per plant, 324,398.29, 40,188.65, 22,383.13, 36,054.58 and 61.95 microg per plant separately. But the highest value of B occured in September and the value was 8 690.97 microg per plant. (2) the distribution of mineral element in the kirilowii plant was not even, the contents of K and P were highest in kirilowii peel, they can reach 27.65 and 2.63 mg.g-1. The contents of Ca and Mg were highest in kirilowii leaves, they can reach 33.28 and 5.73 mg .g-1. The contents of Fe, Mn, B were highest in kirilowii roots, they can reach: 4,069.74, 127.73, 24.75 microg.g-1. The contents of Zn and Mo were highest in kirilowii seeds, they can reach 68. 61 and 1.07 microg.g-1. (3) the cumulation dynamic of mineral elements in kirilowii plant during the whole stages was S-type, and the plant showed rapid growth from the mid-July to mid-Spetember. The information of this study will supply a scientific data for the quality assessment and rational fertilization of kirilowii plant and harvestment.

[Photosynthesis and transpiration characteristics of female and male Trichosanthes kirilowii Maxim individuals]

A field research was conducted on the photosynthesis and transpiration characteristics of dioecious Trichosanthes kirilowii individuals at four key development stages. At vegetative growth stage, the photosynthesis rate, transpiration rate, stomatal conductance, and water use efficiency of male individuals were higher than those of female individuals, and hence, male individuals entered into reproductive growth stage 22 days earlier than female individuals. After entering into reproductive growth stage, male individuals had higher photosynthesis rate, transpiration rate, and stomatal conductance, but slightly lower water use efficiency than female individuals. As the female individuals started to reproductive growth, their photosynthesis rate and water use efficiency were significantly lower, while the transpiration rate and stomatal conductance were higher than those of the male individuals. The effects of climate factors on the growth and development of T. kirilowii mainly occurred at its vegetative growth and early reproductive growth stages, and weakened at later reproductive growth stages. Higher temperature and lower relative humidity benefited the growth and development of T. kirilowii, and illumination could enhance the photosynthesis rate of T. kirilowii, especially its male individuals. After entering into reproductive growth stage, the photosynthesis rate of male individuals increased significantly with increasing illumination, but that of female individuals only had a slight increase, and the transpiration rate of male individuals as well as the photosynthesis rate of female individuals all increased significantly with increasing temperature.

Biosynthesis and bioactivity of trichosanthin in cultured crown gall tissues of Trichosanthes kirilowii Maximowicz

Trichosanthin (TCS) from Trichosanthes kirilowii Maximowicz (T. kirilowii) can be used to treat choriocarcinoma. In this work, we established a novel system to produce TCS in crown gall tissues of T. kirilowii infected by Agrobacterium tumefaciens C58 (A. tumefaciens). In the crown gall tissues, a nopaline synthase (NOS) gene of A. tumefaciens was identified by polymerase chain reaction (PCR), and nopaline accumulation was confirmed by a high-voltage filter paper electrophoresis. Furthermore, we optimized conditions to culture the crown gall tissues able to grow fast and produce TCS in an auxin-free medium, and found that a fungal elicitor of Armillaria mellea was capable of stimulation of TCS secretion into the medium. Moreover, we identified that the TCS purified from the crown gall tissues could induce gastric cancer cell death. These data underscore the usefulness of our system as an inexpensive and virtually unlimited source of TCS.

[Tissue culture and rapid propagation of Trichosanthes kirilowii]

OBJECTIVE

To study tissue culture of Trichosanthes kirilowii, and establish the technique of rapid propagation.

METHODS

Cluster buds were induced from stem tip and stem with axillary bud, calluses were induced from stems and leaves.

RESULTS

Cluster buds could be induced on both the bud and axillary bud from 2-years-old tuber of Trichosanthes kirilowii with MS medium containing 2 mg/L BA and 0.5 -0.05 mg/L NAA. The roots could be induced with MS + 0.1 mg/L NAA + 0.2 mg/L IBA. The seedling with roots could be transplanted after domestication, and achieved the rapid seedling propagation. Calluses could be induced from the stems and leaves with MS + 4 mg/L BA + 0.5 mg/L NAA, and the calluses then could be differentiated into seedlings without root.

CONCLUSION

The male and female seedlings of Trichosanthes kirilowii can be propagated largely using stem tip or axillary bud in short period. The technique of rapid propagation on Trichosanthes kirilowii have a high benefit and low costs.

[Studies on micromorphological characters of fruit coats in cultivated Fructus Trichosanthis in Shandong Province]

OBJECTIVE

To explore the affinity relation among land race of Trichosanthes kirilowii and to provide evidence tor the classification and authentication.

METHOD

Using scanning electron microscope, characteristics of the pericarp surface were studied comparatively.

RESULT

The pericarp surface of the cultivated Fructus Trichosanthis in Shandong showed the characteristics of generality and diversity.

CONCLUSION

The results of the study could be used for the identification of the cultivated Fructus Trichosanthis in Shandong.

[Study on isozymes of farm cultivars of Fructus trichosanthis from Shandong]

OBJECTIVE

To determine different cultivars of Fructus trichosanthis of Shandong, and explore their genetic relationships.

METHODS

The peroxidase isozyme and esterase isozyme of cultivars and wild plant were studied by means of polyarcylamide gel electrophresis, and the finger-prints were established.

RESULTS

The zymogram of the peroxidase isozyme and the esterase isozyme of different cultivars and wild plant of Frustus trichosanthis consisted of common bands, but they had more or less difference in the number of isozymic bands, their positions and activity intensity.

CONCLUSION

There are closer genetic relationships between Niuxin Gualou with Ren Gualou, and Xiao Guang-dan with wild sample; Mingpi and Xiao Guang-dan are two different cultivars; The isozyme analysis can provide reliable basis for determining different cultivars of Fructus trichosanthis of Shandong.

[The tissue culture of medicinal plant Trichosanthes kirilowii and its protein analysis]

We reported preliminary results of rapid propagation, callus induction and regeneration of Trichosanthes Kirilowii, and its protein analysis. Pre-existing meristerms regenerate shoots very rapidly when grown on MS medium containing 0.5 or 1.0 mg/L 6-BA; calli could be induced from leaf sections when put on MS medium containing 4.0 mg/L 6-BA + 0.2 mg/L IAA; shoots regenerated successfully 30 days after calli induction and the differentiation ratio was one shoot out of every four leaf sections; and all shoots gave rise to roots after removing onto MS medium containing 0.1 mg/L NAA and 100% survived when transplanted into soil. Very excitingly, these plants produced small tubers in one month, where satisfactory expression of TCS protein was detected by Western blot analysis.

[Genetic transformation of hairy roots in Trichosanthes kirilowii Maxim. by Ti and Ri plasmids]

OBJECTIVE

To establish a hairy root culture system by double transformation for Trichosanthes kirilowii.

METHOD

1. Crown galls were induced by direct infection of sterile seedlings of T. kirilonii with Agrobacterium tumefaciens C58, and then the hairy roots were obtained from the regenerated plants by infection with A. rhzogenes 15834; 2. Transformation of Ti and Ri plasmids was inspected by high-pressure-paper electrophoresis; 3. The protein contents in the tissues of T. kirilowii were inspected by spectrophotometer and SDS-PAGE.

RESULT

A hairy root culture system has been established successfully by double transformation with Ti and Ri plasmids in T. kirilowii.

CONCLUSION

Compared with the ordinary hairy roots, the double transformed hairy roots grow faster but retain similar protein contents.