The Relationship Between The Microbial Community Of Rhizosphere Soil And The Active Components Of Plants During The Growth Of Aconitum

Aconitum carmichaeli is a perennial herb of medicinal plants, belonging to Ranunculaceae Aconitum taxonomically. A. carmichaeli is one of the important traditional bulk herbs, its root usually as the medicine, and its metabolites alkaloids have various pharmaceutical effect. Nowadays, many aspects of the research on aconite has been launched, but the research about the accumulation of active ingredients in aconitum growth process, while the relationship between soil environmental (especially the soil microbial community) is still rare. It is necessary to grasp the active ingredients accumulated variation of A. carmichaeli and its synergy relationship between the soil microbial community, which is good for this important medicinal plant resources (A. carmichaeli) scientific cultivation and management, as well as providing the further development and utilization reference guide.This study chooses the different developmental stages [fibrous roots growing period(referred to as XGSZ), stem-leaf growing and tuber birth growing period (referred to as KGXC), stem-leaf rapid growing and tuber expanding period(referred to as KGPD), flowering and fruiting period (referred to as KHJG)] of the potted A. carmichaeli as the objects. Determination of rhizosphere soil MBC by chloroform fumigation technique; Using denaturing gradient gel electrophoresis (PCR-DGGE) technical analyze rhizosphere bacterial community composition structure and the diversity (Patrick index S, Pielou index J and Shannon -Weiner index H); using high performance liquid chromatography (HPLC) to determine the contents of five main alkaloids [benzoylmesaconine (BMA), benzoylaconine (BAC), mesaconitine (MA), aconitine (AC), hypaconitine (HA)] about acrial part and underground part in different developmental stages; the method of mathematical statistics and multivariate analysis are used to Study the relationship between the changes in root rhizosphere soil microbial communities associated with plant active ingredients in A. carmichaeli growth process. The main results are indicated as follows:1. Rhizosphere soil microbial community structure and diversity characteristics and changes rules in A. carmichaeli growth process.(1) the number of rhizosphere bacteria bands and the common bands are significantly more than that of control soil in every development stage; A. carmichaeli rhizosphere bacteria community Patrick index (S) and Shannon-Weiner diversity index (H) are significant difference between different developmental stages (P< 0.05), from XGSZ to KHJG stage, these two indexs are present decreasing→rising change trend, and reach the maximum in KGPDand KHJG stages. A. carmichaeli rhizosphere bacteria community Pielou index J is no significant difference between different developmental stages (P>0.05); (2) the trend of control soil bacteria community diversity indexs (S, H and J) are similar to rhizosphere, but the coefficient of variance (CV) of these three diversity indexs in control soil are greater than that of rhizosphere soil; (3) Cluster analysis showed that KGPD and KHJG stage are the most similar, KGPD-KHJG and KGXC stage second, KGPD-KHJG-KGXC and XGSZ stage are the lowest similarity.2. Rhizosphere soil microbial biomass composition and variation in A. carmichaeli growth process.(1) Variance analysis showed that Soil MBC content is significantly influenced by two factors of soil utilization and time (P<0.01), and there is significant interaction between these two factors. (2) The A. carmichaeli rhizosphere and control soil MBC content are all significantly different in different developmental stages (P<0.05), The content of rhizosphere soil MBC in KGPD stage is significantly higher than that in the other three stages (P<0.05). (3) A. carmichaeli rhizosphere and control soil MBC are extremely significant difference in each development stage (P<0.01); the MBC of rhizosphere soil is significantly higher than that of control soil in XGSZ and KGPD stage (P<0.05); On the contrary, the MBC of rhizosphere soil is significantly lower than that of control soil in KGXC and KHJG stage (P<0.05).3. Composition and variation of plant biomass and active components in A. carmichaeli growth process.(1) A. carmichaeli biomass increase significantly from KGXC stage to KGPD stage (P<0.05). (2) The contents of 5 alkaloids in the underground part are higher than those in the acrial part; Underground part of alkaloids content from high to low performanced as: HA>BMA>BAC>MA>AC; the acrial part performanced as MA >BAC>HA>AC>BMA; the whole plant performanced as:HA>AC>MA>BAC >BMA. (3) Whether underground part and acrial part or the whole plant,5 alkaloids content show the different changing trends, and the highest content of these 5 alkaloids appear in different developmental stages, respectively. (4) PCA analysis showed that during the growth process of A. carmichaeli, the aerial part, underground part and the whole plant have the different alkaloids composition pattern, respectively.4. Relationship between rhizosphere soil microbial community and 5 alkaloids in Aconitum growth process.(1) Except for BMA and HA are extremely significant positive correlation (P< 0.01), the rest are not related (P>0.05)during the growth process of A. carmichaeli underground part; BAC and MA, BAC and AC are significantly negative correlation, respectively. (P< 0.05), while the BMA with HA, MA and AC are extremely significant positive correlation (P< 0.01) during the growth process of A. carmichaeli aerial part.(2) 5 alkaloids in A. carmichaeli underground and aerial part and rhizosphere bacteria exist different regression relationship between diversity and biomass. Significant regression relationship between microbial communities and alkaloids:① The optimal regression equation for the BAC of underground part is:BMAunderground= 0.445-0.020S+0.001MBC。②The optimal regression equation for the BAC of acrial part is: BACaCacrial=-0.525+0.184H. ③The optimal regression equation for the MA of underground part and aerial part is: MAunderground= 2.524-0.0595-0.002MBC, MAacrial =-2.463+0.1455-3.553H+10.308J. ④The optimal regression equation for the AC of aerial part is: ACacrial=-0.908+0.0425-1.035H+3.200J. ⑤The optimal regression equation for the HA of underground part is: HAundergound=-5.190-0.0935-0.003MBC +3.049H.Research shows that aconite has obvious rhizosphere effect on soil bacterial community, which promotes the increase of the number and diversity of bacterial species. The number of soil bacteria is affected by changes in the period of development, but also influenced by aconitum plant growth activity. The aconite growth makes the structure and composition of soil bacterial more stable. There are more differences of soil bacterial community structure in different development stages, differences of the size (development) in accordance with the time sequence change in turn, there are little few change of bacterial community in the development period after the second stage. For soil MBC, A. carmichaeli growth has significant effects on soil MBC content, and along with the development of changes in significant changes. In the period of XGSZ and KGPD, aconite has a positive rhizosphere effect on MBC content, promoting a significant increase of soil MBC; In the period of KGPD and KHJG, it has a negative effect on MBC content, inhibitting a significant decrease of soil MBC, which indicates that different stages have different metabolic activity changes, and it can produce different metabolites, and the combined effects of soil, promote or inhibit the growth of soil microbes. For A. carmichaeli biomass and 5 alkaloids, High content of alkaloids in Aconitum roots are used medicinally; The composition and content of alkaloids is different in different parts of the structure, it can choose to use. The peak of the underground parts of five alkaloids accumulation vary from different alkaloids, A. carmichaeli growth period should also be taken into consideration for making full use of different alkaloids when choose it. Regression equation reflect the growth process of A. carmichaeli, it exists a complex quantitative change relationship between the plant body and underground parts of five alkaloids and soil microbial community diversity and biological amount, partial regression coefficient of the positive and negative display whether the two direction change is consistent or not, and the absolute value showed the influence degree of the alkaloid content.