Temporal and Spatial Dynamics of Changes in Chemicals Induced by Pinus massoniana

3:A. The stress response mechanism of plants under insect or environmental stress is an important issue in the research of the relationship between plants and herbivorous insects or environmental effects, and it is also one of the current research hotspots. In recent years, a large number of studies have shown that plants that are harmed by pests can cause physiological stress responses in plants and produce resistant substances such as tannins, phenolic acids, and protease inhibitors that have a defensive effect on insects. However, this stress response of plants is not a continuous non-fund project: the National Natural Science Key Fund (Grant No. 39230290) and the Corresponding Author of the National Key Laboratory of Integrated Management of Agricultural Insects and Rodents Control, but the fast, intermittent and being Adjusted, reflected in the stress response is a temporal change, 21; At the same time, when the plant is partially affected, the plant's induced insect resistance is transmitted within the individual plant, reflecting a spatial change in the stress process3 , 41 that each plant induced chemical changes have a certain temporal and spatial characteristics.

Pinus massoniana Lamb is an important afforestation species in southern China. Ge Feng reported that Pinus massoniana may cause induction of insect resistance to Pinus massoniana after being harmed by Dendrilimus Walker. This affects the growth and development of Dendrolimus punctatus. Artificial hazard modeling was used in this paper. Systemic studies on the chemical substances that induce Pinus massoniana The characteristics of changes over time and space are designed to provide insights into the ecological processes and mechanisms of the occurrence and development of stress responses in Pinus massoniana and to provide a scientific basis for the ecological management of Pinus massoniana.

1Experimental materials and methods Artificial mixed forest of Pinus massoniana and Pinus elliottii with fertile soil and good growing condition was used as the test site. The timing of the induction of the chemical substance of Pinus massoniana was changed in the well-preserved Pinus massoniana plantation, and the masson pine forest was selected. In each of the four communities, ten pine trees of the same age and close growth were selected as markers, and the labeled tree was subjected to manual leaf cutting using a method of manual leaf cutting. The order was: severely affected area (needle loss). More than 75%), the victim in the middle area (about 50% loss of needles), the victim's slight area (loss of needles 25%) and the undamaged area. In the first, third, fifth, tenth, fifteenth, and thirty-fifty days after processing (1 sampling), the new leaves of the current year and the old ones of the previous year were taken from different directions of each branch from top to bottom for each sample. In the leaves, 3 pine trees were taken from each sample. New and old leaves were separated. The needles were mixed and mixed with each other. The mixture was quickly frozen with boiling water, dried and preserved.

1.3 Spatial changes of induction chemicals in Pinus massoniana In the same experimental area, 3 pine trees with 5 rotation branches were selected. The third branch of branches was cut from the canopy and the leaves were cut manually, and the needles lost about 75%. On the second day after the victim was killed, the new leaves and the old leaf pine needles were taken from each branch. Sample evenly and try to get the pine needles from different parts. Sample Preparation Same as above 4 Method for determination of various substances in needles of Pinus massoniana Sodium tungstate phosphomolybdate method was used for tannin determination, aniline method was used for determination of phenolic compounds, anthrone method was used for determination of soluble sugars, and trace Kjeldahl method was used for protein determination. Fr 2 Results and analysis 1 Changes in the content of inductive chemicals in needles of Pinus massoniana with different degrees of damage over time 1.1 Changes in tannin content in leaves of Pinus massoniana with different degrees of damage over time The tannins are an important class of phenolic compounds in plants. Its main effect on insects is to interfere with intestinal digestion and to inhibit the activity of enzymes, and to affect the digestion of insects' starch. 91 The determination of tannin content in new leaf and old leaves of Pinus massoniana in four different degrees of damage shows that it is not affected. The content of tannins in the needles of Pinus massoniana shows a certain quasi-periodic fluctuation. This fluctuation is the reflection of the physiological state of the plant under natural conditions. After the first 35 days of the manual cutting of Pinus massoniana, the old and new conifers of Pinus massoniana have internal times. The content of tannins in the raw material is gradually increased. Ten days later, the content of tannins in the new leaves returned to their original state. After 15 days, the content of tannins decreased compared with the control group. The rate of decline was related to the loss of leaf strength. The more leaves lost, the higher the rate of decline, and the loss of leaves by 20% 50%. The content of tannins in the needles is almost restored to its original condition. After the leaf was lost, the leaf was slightly different from the new leaf. After 10 days, the tannin content was still higher than that of the control group. After 15 days, the tannin content was lower than that of the control group. After 30 days, the content of tannin in the coniferous leaves was increased. 25% of leaf loss has returned to its original state, 50% and 75% of leaves have not returned to normal. Overall, the change in tannins in old needles is smaller than the change in tannins in new leaves.

The analysis of variance (Table 1) showed that the content of tannins in the new leaf of Pinus massoniana with different degrees of damage was significantly different (P 2.1.4 The content of protein content in the leaves of Pinus massoniana with different degrees of damage changed with time after manual cutting of Pinus massoniana , Masson pine needles pushed in the eggs. Physiophylic not 4 surname Figure H analysis results 栳 d) shows that V / - whether it is a new leaf or old leaves, different leaf loss intensity of the new leaves of masson pine in the first victim after After 351°153° days, the difference in protein content was significant (P 2.2.1 Spatial variation of phenolic content induced in the needles of Pinus massoniana. P. massoniana consists of several different ages of verticillium var. The content of phenolic compounds in the new leaves of different parts of Pinus massoniana increased after the 7th treatment of the third round of cuttings, and the content of phenols in the 145th branch of the old leaves of Pinus massoniana rose. The results of the two-way ANOVA showed that (Table 2 in Table 2), both the new and old leaves, the contents of phenolic compounds in the victim and unaffected masson pine needles were significantly different (F=287.°.°5). New Phenolic Compounds from Masson Pine after Damage Increased, a clear difference in the different parts; old leaves did not change significantly between the different parts.

Content of several substances in different parts of the same plant of Pinus massoniana. 2.2.2 Changes in tannin content induced by needles in Pinus massoniana with space. When simulated damage to the third branch of Pinus massoniana, the old leaves of different parts of Pinus massoniana were singled. The content of Ning increased, especially in the 125th branch, which was the third in the fourth round. The content of tannin in the new leaf of the 124th branch of Pinus massoniana rose and the content of tannin in the third round of the branch decreased. Regardless of whether it is a new leaf or an old leaf, the content of tannins in damaged and undamaged Pinus massoniana contains 7l49/w, P=0.0001; F=7.161, P. Contents of several substances in different parts of the same plant of Pinus massoniana 3.2. 3 Changes of soluble sugar content in needles of Pinus massoniana with space The content of soluble sugar in the new leaves of the first 234-round branches decreased after the 3rd-round branch of Pinus massoniana, and the number of branches in the fifth round increased slightly, while in the old leaves of each round Except for the first branch, the contents of soluble sugars in the remaining rounds were decreased by the two-factor analysis of variance (see Table 2 in Table 3). There was a significant difference between the damaged and unvicinated new leaves of Pinus massoniana (F= 0.0090.05). The contents of soluble sugars in the new leaves were significantly different (F = 15.321, P 3.2.4. Induced protein content in needles of Pinus massoniana with spatial variation indicated that after the third round of masson pine was treated with 75% clipping, the tail was The protein content of the 12th branch of Pinus sylvesii leaves was reduced, the content of the third 45th rosewood increased, the protein content of the 123rd leaves of the old leaves increased, and the protein content of the 4th round of branches was decreased. After two-factor analysis of variance (see Table 2 Table 3). ), between the damaged and undamaged new leaves of Pinus massoniana The difference was not significant (F = 0.092> 0.05); but there was a significant difference between the old leaves of the damaged and undamaged leaves of Pinus massoniana (P < 0.05). The protein content of the new leaves in different parts showed significant differences (F = 203.997, P). Table 2 Different parts of the same plant of Pinus massoniana Several species within the new leaf content analysis of variance in the form Ning victims Damage phenols soluble glycoprotein 3 Summary and discussion The plant itself is in a basal metabolism and secondary metabolism in the process of alternating open changes, unaffected masson pine needles Both nutrients and sub-biomass are constantly fluctuating, which is a normal physiological process. The plant's resistance function is also present in this dynamic process of change. The content of substances (tannins and phenols) constantly fluctuate, increase first and then gradually decrease;the soluble sugar content of nutrients decreases first, then increases, and then recovers to the original level.The synthesis of secondary metabolites requires the consumption of energy and substances. It will inevitably affect the main metabolism of the plant.The energy and materials used by the plant for defense are limited, and the mass The response was not continuous and controlled but was rapid, intermittent, and regulated, reflecting the fact that the stress response process of Pinus massoniana was a kind of tense change. The severity of the damage had a certain influence on the change of chemical substances induced by Pinus massoniana. When there were 2 losses in the coniferous leaves of Pinus massoniana, the induced chemicals were changed in the needles of Pinus massoniana, the content of secondary metabolites was increased, and the content of nutrients was decreased, indicating that the plants were always in a state of alert, and once the stimulation exceeded the threshold, they were immediately adjusted. When the needle loss was 50%, the secondary metabolites increased most in the needles of Pinus massoniana, indicating that there was a suitable degree of damage, and the ability to induce chemical changes in plants was the strongest. Metabolism and nutrient content are close, with little difference, indicating that within a certain extent of damage, the intensity of induced chemical changes exhibited by plants will be basically the same and that the induced chemical changes and damage degree of plants will present a kind of “open-close”. The (n-ff) effect of secondary metabolites has a certain correlation with the reduction of nutrients. When the plants are victimized, the plants will transfer the nutrients in mature old stems and leaves to other parts. Therefore, the old leaves of Pinus massoniana are reduced more than the soluble sugars in new leaves and other young tissues.

The changes in induction chemicals of Pinus massoniana have significant spatial heterogeneity in addition to their time series. When the third round of masson pine was victimized, changes in induced chemicals were also generated in the remaining rounds of Pinus massoniana. Due to the different parts of the verticillium, the whole plant was present and distributed unevenly, showing the induction Chemical defenses are a whole response.

Table 3 Analysis of the variance of several substances in the old leaves of different parts of the same plant of Pinus massoniana. Form Ning victim Phenolics Damage degree Damage Vulnerable sugar Victim protein damage