Influence of Endogenous carbohydrate content on Initiation of adventitious roots in stem cuttings of Coleus blumei L.
Associate Professor, Faculty of Science, Programme of Botany, Assam Down Town University,
Gandhinagar, Panikhaiti, Guwahati - 26 Assam, India.
*Corresponding Author E-mail: mrinal_kumar06@rediffmail.com
ABSTRACT:
Several internal and externally administered substances may stimulate or prevent the development of adventitious roots. The present study was conducted to analyze the role of endogenous carbohydrate content on the initiation of adventitious roots during the culture of Coleus blumei L. stem cuttings. The stem cuttings of the plant were cultured at various inclinations viz., 22.50, 450, 67.50, 900 and 1800 to the soil surface. The endogenous carbohydrate content in water was analyzed from stem cuttings (4cm length) on the initial day and after 4 days of culture of Coleus blumei L cuttings. At the base of the cultured cuttings, up to the 2 cm area of root initiation, the carbohydrate (glucose) amount exhibited variations along with inclinations. Additionally, a substantial relationship was found between the gravity component and the endogenous glucose level. Although the maximum amount of carbohydrate accumulation (325µg/g F.W.) was recorded at a 22.50 inclination, its subsequent accumulation at 450 inclination (256µg/g F.W.) exhibited a fast genesis of adventitious roots. This presumably indicated that the components of gravity (g), viz. pgsinθ and pgcosθ had a significant influence on the rate of transportation of endogenous carbohydrate content to the basal terminal part of the cultured cut sections that are maintained at varied inclinations. Accumulating carbohydrates at the base of cultured cuttings influences the development and maturation of adventitious roots in stem cut sections. Nonetheless, the research showed that the beginning of the rooting process in stem cuttings of Coleus blumei L. necessitates a certain quantity of endogenous carbohydrates.
KEYWORDS: Cuttings, Inclinations, Endogenous carbohydrate, Adventitious roots, Gravity components.
INTRODUCTION:
Induction of adventitious root in resected plant section is a bottleneck for the viability of the separated plant parts and indispensable in cuttings of vegetative propagation of horticultural and agricultural plants1. Two key elements are essential for the effective growth of adventitious root formation: the required auxin (either internal or administered) and a tissue oriented to root formation2. Apart from these two, cuttings from a well-developed healthy stem may have different rooting potential depending on the level of hormones, carbohydrates, the presence of minerals, genotypes, cutting position on the shoot, and other variables3,4.
Further, root production is greatly influenced by the orientation and rooting medium of the excised stems5. If the cuttings are kept horizontally (1800), roots are seen to develop almost the whole length of the stem on the lower surface of the cuttings; however, when they are nurtured vertically (900), roots are only seen to develop at the bottom ends. The basipetal movement of Auxin is believed to be responsible for this polarity of roots of stem cuttings. When the clipped part is segregated from the donor plant, auxins are heaped up at the cuttings' basal portion of the cuttings5,6. Concomitantly, the heaped-up auxins trigger the build-up of carbohydrates, which mainly contribute to the carbon backbone and energy source for the early phases of developing adventitious roots and healing wounds7-13. Consequently, Auxin and Carbohydrates interact during the beginning phases, generating a fresh carbohydrates trap at the bottom of the incision14. Moreover, the basipetal movement of Auxin is greatly influenced by the gravity15. The force of gravity (g) is the key factor in geosensitive plants consisting of magnitude and direction16,17. Vendrig has reported that the longitudinal flow of substance in the Coleus stem is governed by gravity18. Aside from these incongruous hypotheses, the hormones necessary for root initiation are collected at the cuttings' basal ends due to gravitational force have not been quantified; hence, no association between hormones and root initiation can be determined18-20 Furthermore, no research has been done on how gravity individually affects (pgsinθ or pgcosθ) the movement and buildup of endogenous carbohydrate content, which is a key factor in developing adventitious roots following severance. This study aimed to evaluate the influence of endogenous carbon content on the onset of adventitious roots in Coleus stem cuttings maintained at varied angles to the soil's surface. Additionally, an association between endogenous carbohydrates and gravity was examined.
The stem cuttings were taken from healthy Coleus blumei L. plant branches of related age and size. Unscathed apical bud of 4cm stem cutting and 5 leaves were used for the experiment21. Stem cutting was cultured at the impenetrable bottle at 22.50, 450, 67.50, 900 and 1800 to the surface of the soil21 and placed in dispersed sunlight for 4 days to investigate the glucose content accumulated from day 0 to day 4.
Glucose content at 2cm length was estimated from the pedestal end of cultured cutting as the initiation of rotting is confined up to 2cm length22 and ultimately quantified by TLC method with n-butanol: acetone: water: 4:5:1 as a solvent and scanned by IATRO TH-10 with a computer.
The experiments were conducted 3 times with 5 replicas. The carbohydrate amount was determined as µg/gram of fresh weight (F.W.)
The average results are presented in Table 1
According to the findings in Table 1, inclinations significantly impact the concentration of endogenous glucose in cultured Coleus blumei L. stem cuttings.
Table 1: Representing outcome of gravity contents on quantity of endogenous glucose (µg/g F.W.) in stem cuttings of Coleus blumei L.
|
Degree of inclination with soil surface |
Glucose content (µg/gF.W.) |
|
|
0 Day |
4 Day |
|
|
22.50 |
254 |
412 |
|
450 |
254 |
325 |
|
67.50 |
254 |
256 |
|
900 |
254 |
243 |
|
1800 |
254 |
169 |
DISCUSSION:
The auxin-carbohydrate crosstalk as the primary mechanism involved during the early phases of adventitious rooting in cut fragments is a widely acknowledged fact. However, observing that the cuttings cultivated at 22.50 showed the maximum glucose level (412µg/g F.W.) of all tested inclinations was captivating. Though the cuttings oriented at the inclination of 450 quickly generated vast quantities of roots, even the longest stretch of roots could not demonstrate a remarkable amount of glucose23. Thus, it could be suggested that a suitable amount of glucose at the basal end of the cuttings was required for fast rooting in the cuttings of Coleus stem11. The cuttings' greater or lesser glucose level impeded root induction and slowed their eventual growth. Contrarily, the amount of glucose in the stem cuttings with higher inclinations gradually declined, with the lowest amount (169µg/g F.W.) occurring at the highest inclination of 1800. Gravity generally affects how glucose in leaves is transported basipetal to other parts of an erect plant. Nevertheless, a cutting with just one branch or stem grown at 900 from the ground differs quite from an entire plant with branches that emerge from the central stem at various angles. The total gravity capable of propelling a substance cultured at 900 to the soil surface, i.e., from the pinnacle to the lowest portion, will be Ig. It is well known that in the matter of inclination, gravity dissociates into force components: pgsin𝜃 and pgcos𝜃 (where 𝜃 is the angle of inclinations of the cuttings). Thus, Ig is greatly diminished for the cultures inclined at 22.50, 450, 67.50, 900 and 1800. Consequently, the values of pgsin𝜃 and pgcos𝜃 will change with each change in 𝜃. In terms of glucose build up, pgsin𝜃 is more potent than pgcos𝜃. As such, pgsin𝜃 is merely responsible for transporting carbohydrates from the higher part to the bottom of cultured cuttings.
CONCLUSION:
Even though carbohydrate is the primary requirement for cell growth, increased glucose buildup does not always hasten the onset of the rooting process. In a nutshell, a threshold amount of glucose is vital for cell processes for the denovo regeneration of adventitious roots. Further research can be done to study the role of different carbohydrates and their interactions and complexes with other molecules to enhance the rooting percentage in this economically important plant.
I thank Prof. Dr. C. L. Boissya, Professor and Former Head of the Department of Botany, Gauhati University, for his guidance and support.
CONFLICT OF INTEREST:
The author declared that there is no conflict of interest.
REFERENCES:
1. Druege U, et al. Molecular and physiological control of adventitious rooting in cuttings: phytohormone action meets resource allocation. Annals of Botany. 2019; 123(6): 929–949. https://doi.org/10.1093/aob/mcy234
2. Devi N.A, et al. Enzymatic synthesis of ethylButyrate in supercritical carbondioxide using surface coated Lipase from Candida rugosa. Int. J. Tech. 2011; 1(2): 72-75
3. Druege U, et al. Molecular and physiological control of adventitious rooting in cuttings: phytohormone action meets resource allocation. Annals of Botany. 2019; 123(6): 929–949. https://doi.org/10.1093/aob/mcy234
4. Pijut PM, et al. Promotion of adventitious root formation of difficult-to-root hardwood tree species. In Jules J. Horticultural Reviews, edited by Wiley-Blackwell, Oxford, UK. 2010; 213–251.
5. Gorala M.G. et al. Effect of Rotation on free connective flow on vertically upwards heated plate with Gravity Modulation in Slip Flow Region. Int.J.Tech. 2014; 4(1): 11-14
6. Huang A, et al. Reactive oxygen species regulate auxin levels to mediate adventitious root induction in Arabidopsis hypocotyl cuttings. Journal of Integrative Plant Biology. 2020; 62: 912–926. doi: 10.1111/jipb.12870
7. Kumar A, Choudhary et al. Chapter 1—Physiological and environmental control of adventitious root formation in cuttings: An overview. In: Husen A. Environmental, Physiological and Chemical Controls of Adventitious Rooting in Cuttings, edited by Academic Press; Cambridge, MA, USA. 2022; 1–24.
8. Monder MJ, Pacholczak A. Rhizogenesis and concentration of carbohydrates in cuttings harvested at different phenological stages of once-blooming rose shrubs and treated with rooting stimulants. Biological Agriculture and Horticulture. 2020; 36(1): 53–70. doi: 10.1080/01448765.2019.1685407
9. Ahmed A., Tomar G.S. Response of Phosphatic fertilization on Cowpea cultivars for fodder productionunder vertisolconditions of C.g.plains. Research J. Scienceand Tech. 2009; 1(3): 97-99.
10. Raj B.,et al. Quantitative Estimation of Rosmarinic Acid in Ocimum sanctum Extracts and Polyherbal Formulation by HPTLC. Research Journal of Pharmacognosy and Phytochemistry. 2010; 2(1): 46-48.
11. Shankar G et al. Growth and Instability: An Inter Zonal Analysis of Kharif and Rabi Crops in Chhattisgarh. Research J. Engineering and Tech. 2010; 1(1): 18-23.
12. Sehgal B., Kunde G.B. Grafting enhances the thermal stability of thermoplastic elastomers. Research J.Engineering and Tech. 2010; 1(2) Oct-Dec: 65-69.
13. Sravan M et al. Quantitative Evaluation of Carbohydrate Levels in different Natural Food stuffs by UV-Visible Spectrophotometer. Asian J. Pharm Ana. 2012; 2(1): 10-11.
14. Roussos PA. Adventitious Root Formation in Plants: The Implication of Hydrogen Peroxide and Nitric Oxide. Antioxidants (Basel). 2023; 12(4): 862. doi: 10.3390/antiox12040862
15. Lyon C J. Gravity factor for auxin transport. Science. 1962; 137(3528): 432-3. doi 10.1126/science.137.3528.432
16. Dedolph R R, et al. Effect of gravity compensation on the geotropic sensitivity of Avena seedlings. Plant Physiology. 1965; 40(5): 961. doi 10.1104/pp.40.5.961
17. Mannem K et al. Quantitative Evaluation of Carbohydrate Levels in Green Leafy Vegetables for Home use by UV-Visible Spectrophotometer. Asian J.Pharm Ana. 2012; 2(3): 79-80
18. Vendrig J C. On the abscission of debladed petioles in Coleus rhenaltianus, especially in relation to the effect of gravity. Wentia. 1960; 3(S1): 1-96 . doi.org/10.1111/j.1438-8677.1960.tb00003.x
19. Madhu CH et al. Quantitative Evaluation of Carbohydrate Levels in Seeds for Home Use By UV Visible Spectrophotometer. Asian J.Pharm Ana. 2012; 2(4): 104-105
20. Eslavath R at el. Phytochemical Screening and TLC, UV-Spectrophotometer study of Bougainvillea glabra. Asian J. Pharm Ana. 2013; 3:8 3-85
21. Boissya CL, Das MK. Effect of gravity on the initiation and growth of adventitious roots in Coleus blumei L stem cuttings. Neo Botanica. 1993;.1: 47-54
22. Loomis WE, Shull CA. Methods in Plant Physiology. 1937
23. Denaxa NK, et al. The role of endogenous carbohydrates and seasonal variation in rooting ability of cuttings of an easy and a hard to root olive cultivars (Oleaeuropaea L.). Scientia Horticulturae. 2012; 143: 19-28. doi.org/10.1016/j.scienta.2012; 05.026
Received on 06.11.2023 Modified on 07.03.2024
Accepted on 13.06.2024 © RJPT All right reserved
Research J. Pharm. and Tech 2024; 17(11):5424-5426.