Metabolites of Terrestrial Plants and Marine Organisms as Potential Regulators of Growth of Agricultural Plants in the Russian Far East

Growth regulating activity of metabolites of terrestrial plants and marine organisms – water, alcohol and lipidic extracts, polysaccharides, diterpene, triterpene and steroidal glycosides, alkaloids, pigments, decumbenones and β,β'-triketones were studied. It was defined that some of the studied substances are capable to stimulate, inhibit or be inactive in relation to the main root of seedlings of agricultural plants. Extract and triterpene glycoside of hederagenin cauloside C, isolated from Caulophyllum robustum Maxim., and monosulfated cucumariosides group A2, isolated from of the Far Eastern edible holothurian Cucumaria japonica, inhibit the growth of seedlings the main root of Cucumis sativus. Among of decumbenones A (1), B (2) and C (3), isolated from the marine-derived strain of the fungus Aspergillus sulphureus, decumbenone A (1) stimulates the growth of seedling roots of Triticum aestivum and Zea mays. Among of alkaloids 1-9, isolated from the marine fungus Aspergillus fumigatus, of alkaloid 3 stimulated the growth of seedling roots of Оrysa sativa and Fagopyrum esculentum. The water extracts of F. esculentum (of the red-stem population) at a concentration of 10 g/ml stimulated productivity of one plant F. esculentum by 67% and content of rutin in F. esculentum plants by 20% more than in the control.


Introduction
One of the promising directions in agriculture is rational use of local raw material sources for biologically active substances -plant growth stimulators.Plant growth stimulators improve seed germination, seedling development, accelerate growth and yield of the plants (Kumari et al., 2011;Craigie, 2011;Ahmed & Shalaby, 2012;Yurchenko et al., 2013).They are used against pests (Hong et al., 2007) and plant diseases (Jayaraj et al., 2008).They also increase plants resistance to environmental stresses (Zhang & Ervin, 2004, 2008).It is obvious that the main focus should be on the first stages of plant ontogenesis, beginning with seed germination and seedling growth.In the early stages of plant growth is well developed root system provides a sound basis for the value and quality of future crop.Therefore the search for the most effective substances that stimulate its development, should be considered as a priority.
Natural world of the Far East has great potential for the detection and isolation of biologically active compounds that can increase productivity of agricultural plants in the zone of risky agriculture.Terrestrial plants, algae and marine microorganisms can be sources of such biologically active substances.

Extracts of Terrestrial Plants
A wide spectrum of medical and biological actions of ginseng roots (Panax ginseng C. A. Meyer) is connected with the presence of triterpene glycosides of dammarane and oleanolic series -ginsenosides and panaxasides (Uvarova et al., 2000).However, effect of ginseng roots extracts on plant cells are shown for the first time.The results showed that while having the extracts in concentration of 0.1 and 1.0 mg/ml, the average length of the main root of Cucumis sativus seedlings decreased by 8.0, 11.5%, respectively.Extracts have primarily effective influence on rapidly growing seedlings.At the same time, slow growing seedlings were not sensitive to high concentrations of these substances (Аnisimov et al., 2003).
East Asian plant Caulophyllum robustum Maxim, family Berberidaceae Juss., is a source of biologically active substances with a wide range of medical and biological action (Аnisimov et al., 2000а).Here is the data influence of water-alcohol extract (WAE) made of roots and rhizomes of Caulophyllum robustum upon growth of the main root seedlings of C. sativus (Аnisimov et al., 2000b).WAE had a significant inhibitory effect on the growth of the main root seedlings of C. sativus at concentrations 0.003% and 0.03%.Vigorously growing seedlings are the most sensitive to the inhibitory action of WAE.Thus, WAE reduced the number of sprouts with the root length of 61-80 and 81-100 mm by 70 and 100% at a concentration of 0.003 and 0.03% respectively.Seedlings with slowly growing roots were insensitive to high concentrations of WAE.
The authors studied effect of the extracts of F. esculentum (red-stem and red-flower population) -10 -8 g/ml and (pink-flower population) -10 -6 g/ml) upon the growth and development of F. esculentum in blooming stage.The results showed that extracts of F. esculentum (red-stem population) at concentration of 10 -8 g/ml had maximum stimulating effect upon increasing productivity of one plant till 59-67%, and rutin content by 20% more than in the control.Extract from pink-flower population of F. esculentum at concentration of 10 -6 g/ml stimulated maximum increase of 1000 grains weight of F. esculentum by 17.7% in comparison with the control (Klykov et al., 2014).
The authors studied effect of plant polysaccharides of Ampelopsis japonica Thunb (1), Angelica dahurica (liisch.ex Hoffm) (2), Glehnia littoralis F. Schmidt (3), Heracleum moellendorffii Hance (4), Saposhnicovia divaricata (Turez) (5) and F. esculentum Moench (6) upon the main root of C. sativus seedlings growth.By activity they can be divided into three groups.The first group includes polysaccharides that stimulate root growth.These are polysaccharides of aqueous, oxalate and alkaline extractions from roots of A. dahurica, aqueous extraction of G. littoralis roots and alkaline extraction from F. esculentum fruit shells.The second group of polysaccharides inhibited the roots growth.It includes polysaccharides of alkaline extraction from roots of A. japonica, of oxalate extraction from roots, and of water, oxalate and alkaline extractions from H. moellendorffii stems, and of water extraction from leaves and stems of S. divaricata.Polysaccharides of the third group had no significant effect upon the growth of seedling roots of S. sativus (Аnisimov et al., 2005).

Seaweed
Seaweeds resources are intensively used to improve harvest quantity and quality in agriculture and horticulture.Beneficial effect of seaweed products on cultivated plants has been studied well.Usage of seaweed products improve seeds germination, seedlings development and increase plant growth and yield (Hong et al., 2007;Zodape et al., 2008;Khan et al., 2009;Kumari et al., 2011;Craigie, 2011).Seaweeds are used in pests control (Hong et al., 2007) and plant diseases management (Jayaraj et al., 2008).They increase plants' resistance to ecological stresses (Zhang & Ervin, 2004, 2008).Liquid extracts derived from seaweeds gained importance as foliar sprays and soil drench for many crops including various grasses, cereals, flowers (Gandhiyappan & Perumal, 2001;Kumari et al., 2011).
The Far Eastern Marine areas have great biodiversity of algae suitable for food purposes, and for production of pharmacologically active substances and plant growth regulators.Aqueous extracts of marine algae collected at different times of the year, have a stimulating and inhibitory effects on the growth of seedling roots of F. esculentum and G. max (Anisimov et al., 2013;Anisimov & Chaikina, 2014).Extract of red algae Neorhodomela larix, collected in January and May 2012, stimulated growth of seedling roots of F. esculentum by 13 and 12% at concentrations of 10 -5 and 10 -6 g/ml respectively.Extract of red algae Tichocarpus crinitus, collected in May and August 2012, stimulated growth of Fagopyrum esculentum roots by 13 and 17% at concentration of 10 -4 g/ml.
Aqueous extracts of brown algae Saccharina japonica and Sargassum pallidum, collected in January and May 2012, stimulated growth of seedling roots of F. esculentum by 15% and 13% at concentration of 10 -6 and 10 -5 g/ml.respectively.Aqueous extract of green alga Codium fragile, collected in November 2011, stimulated growth of seedling roots of G. max by 18% at concentrations of 10 -5 g/ml.Aqueous extracts of the most algae have inhibitory effect upon growth of seedling roots of F. esculentum and G. max at concentrations of 10 -2 g/ml.Thus, aqueous extracts of algae, depending on the season, have stimulating effect in varying degrees upon growth of seedling roots of F. esculentum and G. max at concentrations of 10 -3 -10 -6 g/ml.
In the bay of Troitsy (the Sea of Japan) in summer there were collected the following sea weeds: Laminaria cichorioides, L. japonica, Fucus evanescens, Dictyopheris divaricata, Costaria costata, Sargassum miyabei, Scaphecinus mirabilis, Punctaria sp., Cocophora langsdorfii, Undaria pinnatifida, Chorda filum, Chordaria flagelliformis.Lipid fractions were derived from these sea weeds.Effect of the lipid fractions upon growth of the seedlings roots of F. esculentum was studied (Anisimov et al., 2010а).It is shown that lipid fractions derived from L. cichorioides, C. langsdorfii, U. pinnatifida demonstrated stimulatory effect on growth of the seedlings roots of F. esculentum by 13, 13-17 and 12-17% at concentrations of 0.01, 0.1-10, 1-100 µg/ml, respectively.Lipid fractions from D. divaricata -had inhibitory effect on growth of the seedlings roots of buckwheat.Extracts of L. japonica and F. evanescens showed stimulatory effect upon growth of the seedlings roots of G. max by 20 and 24%, and upon stem growth -26 and 15%, respectively, at concentrations of 100 µg/ml.These extracts increased productivity of G. max by 15.6 and 11.7%.Extracts of L. sichorioides and C. costata showed less activity.They increased yield by 8.9% (Imbs et al., 2011).
The effect of extractive substances from brown alga L. cichorioides on growth of F. esculentum sprouts, upon the seeds yield and rutin content in plants was studied.Maximum stimulating effect on growth of seedlings roots of buckwheat was made by chlorophyll, fucoxanthin, digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol at concentration of 1 μg/ml.Fractions of polyphenolic compounds, monogalactosyldiacylglycerins, sulfoquinovosyldiacylglycerols, fatty acids and fucoxanthin at concentration of 100 μg/ml had inhibiting effect upon the growth of buckwheat stems.Buckwheat seeds treated with an ethanol extract of L. cichorioides increased yield of F. esculentum (Chaikina et al., 2011).
There was studied effect of laminaran and a number of 1,3;1,6-β-D-glucooligosaccharides of various molecular masses and branching upon germination of seeds and formation of germs of F. esculentum variety Izumrud.It was defined that all the glucans had enhanced the energy of seed germination to various extents and stimulate growth of root of buckwheat germs on the earliest stage (1-2 days).The best stimulating effect had 1,3;1,6-β-D-glucooligosaccharides with the molecular mass of 1661.5, characteristic feature of the structure of which is not only presence of a great amount of β-1,6-linked glucose residues as a kind of branches (1,3 : 1,6 = 3.7 : 1), but also presence of a β-1,6-link inside their main chain (Fedorova et al., 2010).β-D-Glucooligosaccharides and fucoidan from seaweed L. cichorioides and F. evanescens, stimulated productivity of G. max by 0,41 and 0,39 t/ha and reduce length of vegetation period by 3-4 days, compared with the control (Zaostrovnyh et al., 2010).

Diterpene Glycosides
The article presents data on the effect of diterpene glycosides (Table 1) derived from marine fungus Acremonium striatisporum on the growth of seedling roots of Z. mays.Depending on the chemical structure, virescenosides A-V (1-10) have different effects on the growth of seedling roots of Z. mays.
Table 1.Chemical structure of diterpene glycosides derived from marine fungus Acremonium striatisporum Virescenoside A (1) has R 1 = OH, R 2 = H, β-OH.This compound showed a stimulant effect on the growth of seedlings root of Z. mays at a concentration of 10 -5 M (by 13.7%).Virescenoside B (2) has R 1 = H.This compound demonstrated the most effective stimulant effect on the growth of seedlings root of Z. mays at a concentration of 10 -6 -10 -7 M (by 16.0%).Virescenoside C (3) has R 2 = O.This compound showed low stimulant effect on the growth of seedlings root of Z. mays at a concentration of 10 -5 M (by 8.3%).Virescenoside F (4) in contrast to virescenoside A (1), comprises Altruron acid (AltA) as the sugar component, that deprives glucoside 4 of its stimulant effect at a concentration of 10 -5 -10 -8 M. Virescenosides G (5) and Q (9), compared with the glycoside 2, contain respectively AltA and mannose in carbohydrate part.This change for glucoside 5 does not essentially effect on the growth of seedlings root of Z. mays (10 -7 M -12%), but for glucoside 9, this effect significantly decreases (10 -5 M -11%).Virescenoside M (6), N (7), P (8) and V (10) were inactive (Anisimov et al., 2010).There was studied reaction of plant F. esculentum (the root system development, changes of morphological traits, yield and content of routine) under usage of diterpene glycoside virescenoside A and the sum of glycosides in small concentrations (10 -13 -10 -15 M) (Klykov et al., 2013).The maximum stimulant effect on seedlings of F. esculentum (variety Izumrud) was observed at a concentration of virescenoside A of 10 -13 M and the sum of glycosides of 10 -15 M. Stimulant effect of virescenoside A on seedlings of F. esculentum (variety Pri 10) was observed at a concentration of 10 -15 M. Maximum content of rutin in seedlings of F. esculentum (variety Izumrud) was observed at a concentration of virescenoside A of 10 -15 M.
Figure 2. Chemical structure of decumbenones

The Alkaloids 1-9
The article presents data about effect of alkaloids (1-9) (Figure 3), derived from marine fungus Aspergillus fumigatus, upon growth of seedling roots of F. esculentum, G. max and Z. mays.The alkaloid 1 showed a stimulant effect on the growthof seedling roots of F. esculentum by 10% (10 -9 M), G. max by 10% (10 -10 M) and Z. mays by 13% (10 -5 M).The alkaloid 2, in which the 12th and 13th hydroxyl groups are replaced by hydrogen atoms, showed inhibitory effect on the growth of seedlings root of F. esculentum by 14.3% (10 -9 M) and stimulant effect on the growth of seedlings roots of G. max by 12% (10 -12 М) and Z. mays by 8% (10 -9 M).The alkaloid 3 showed stimulant effect on the growth of seedlings roots of F. esculentum by 21% (10 -7 M), G. max by 14% (10 -10 М) and didn't show stimulant effect on the growth of seedlings roots of Z. mays in studied concentrations.The alkaloid 4 showed stimulant effect on growth of seedlings roots of F. esculentum by 14 % and 13 % (10 -7 and 10 -12 M respectively) and didn't show stimulant effect on growth of seedlings roots of G. max and Z. mays in studied concentrations.The alkaloid 5, which differed from alkaloid 1 by additional prenyl residue and endoperoxide bond, showed stimulant effect on growth of seedlings roots of G. max by 10% (10 -7 M) and didn't effect upon growth of seedlings roots of F. esculentum and Zea mays.The alkaloid 6 showed stimulant effect on growth of seedlings roots of F. esculentum, G. max and Z. mays by 17 %, 12 % and 13 % (10 -10 , 10 -10 and 10 -7 M) respectively.The alkaloid 7 showed stimulant effect on growth of seedlings roots of F. esculentum, G. max and Z. mays by 13 %, 16 % and 17 % (10 -8 , 10 -9 and 10 -9 M) respectively.The alkaloids 8 showed the most expressed stimulant effect on growth of seedlings roots of Z. mays by 21, 17 and 18% (10 -15 , 10 -10 and 10 -5 M), respectively, while it didn't effect upon roots of seedlings of F. esculentum and G. max.The alkaloids 9 didn't effect upon roots of seedlings of F. esculentum (Anisimov et al., 2012b(Anisimov et al., , 2013;;Аfiyatullov et al., 2012).

The Triterpenoids of Lupane Series
Influence of triterpenoids of lupane series (Figure 5) upon growth of seedlings roots of C. sativus was investigated.It is shown that these compounds (1-25) hadn't obvious effect of the plant growth regulators in concentrations 0.001-100.00µg/ml (Stekhova et al., 2002;Аnisimov et al., 2006).
Figure 5.Chemical structure of triterpenoids of lupane series

Triterpene Glycosides of Hederagenin
Table 2.Chemical structure of triterpene glycosides of hederagenin There were investigated effects of triterpene glycosides of hederagenin -caulosides A, C, D and G (Table 2), derived from Caulophyllum robustum Maxim.upon root growth of seedlings Cucumis sativus L. Caulosides A and C have one carbohydrate chain.These compounds have inhibitory effect upon the growth of seedlings roots of C. sativus (10.3 and 20.4% respectively) at concentrations of 500 and 100 µg/ml.Caulosides D and G have two carbohydrate chains.These compounds have not inhibitory effect upon the growth of seedlings roots of C. sativus at a concentration of 500 µg/ml.Caulosides D and G have weak stimulant effect at concentrations of 100 (9.1%) and 250 (10.4%) µg/ml respectively.Inhibitory effect of Caulosides C (3) first is directed to the seedlings with intensively growing main root (Аnisimov, Chaikina, in press).

Glycosides of Sea Cucumbers
Representatives of class of sea cucumbers (class Holothurioidea, type Echinodermata) are widely distributed throughout the world's Oceans.More than 70 species of sea cucumbers, mostly tropical, are used as food and in traditional oriental medicine.Cucumaria japonica and Cucumaria frondosa are among the largest and mass species of sea cucumbers and are the objects of fishing in our country (Levin & Gudimova, 1997).The study showed that triterpene glycosides of the Far Eastern edible holothurian Cucumaria japonica (monosulfated glycosides of groups A 2 and A 4 , disulfated subfraction A 6 , trisulfated subtraction A 7 , and the total fraction of monosulfated glycosides including subtractions A 0 , A 1 , A 2 , and A 4 ) inhibit growth of the main root of C. sativus seedlings.Cucumariosides are arranged as follows according to their inhibitory activity: subfraction A 2 (ED 50 53.1 µg/ml) > total fraction of monosulfated glycosides (ED 50 127.4µg/ml) > subfraction A 4 (ED 50 346.5 µg/ml) > subfraction A 6 (ED 50 375.7 µg/ml) > subfraction A 7 (ED 50 539.4µg/ml).It was defined that when glycosides concentration in the medium increases, so the average length of the main root of seedlings decreased due to increase of seedlings number with low growth ability and absolute absence of seedlings with high growth ability (Аnisimov et al., 2004).

Glycosides of Starfish
Starfish (Echinoderms species) are characterized by a large variety of high oxidated steroid compounds.The article presents data on the effect of steroid glycosides 1-3 (Figure 6), derived from the starfish Asteropsis carinifera, upon the growth of seedlings roots and stems of G. max, F. esculentum, Z. mays and Orysa sativa.
Compound 1 showed stimulant effect on the growth of seedlings roots of F. esculentum by 17 and 13% (at a concentration of 10 -5 и 10 -2 µg/ml) and Z. mays -11 and 13% (10 -8 и 10 -5 µg/ml), but did not show stimulant effect upon the growth of seedlings roots of G. max and O. sativa.Compound 2 showed a stimulant effect upon the growth of seedlings roots and sprouts of G. max by 15 and 11% (at a concentration of 10 -1 µg/ml).This compound showed stimulant effect on the growth of the root of О. sativa by 13, 12 and 13% at a concentration of 10 -8 , 10 -4 and 10 -1 µg/ml.Compound 3 showed significant stimulant effect upon the growth of seedlings root of O. sativa by 27% at a concentration of 10 -3 µg/ml (Аnisimov et al., 2012c).
Figure 6.Chemical structure of steroid glycosides of starfish Asteropsis carinifera

Сonclusion
Thus, some of the studied metabolites derived from terrestrial plants and marine organisms in the Russian Far East, as well as drugs, synthesized on their basis are worthy to notice as regulators of growth of agricultural plants.Compounds causing significant growth inhibition of plants are prospective for study as herbicides.Their introduction into practice will increase plant productivity, and hence the profitability of crop production.

Figure 3 .
Figure 3.Chemical structure of alkaloids

Figure 4 .
Figure 4.Chemical structure of triterpene glycosides of dammarane series and their analogues