Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri

Vesile Yalçın; Hülya Torun; Engin Eroğlu; Elmas Ülkühan Usta

doi:10.29130/dubited.1109502

EN TR

Physiological and Biochemical Effects of Drought Stress in Stevia (Stevia rebaudiana Bertoni)

Abstract

Drought has been limiting the productivity of agricultural crops by increasing alarmingly in recent years. This situation has increased the importance of research on the determination of plants resistant to arid conditions. In this study, two cultivars (Yalova and STF-4) of Stevia rebaudiana Bertoni plant were investigated physiological and biochemical responses of under drought stress. Plants were grown in controlled greenhouse conditions for 3 months and then exposed to drought for 3 weeks. The plants harvested after three weeks were measured leaf length, osmotic potential, relative water content (RWC), chlorophyll fluorescence (Fv/Fm), proline amount, hydrogen peroxide (H2O2) amount and lipid peroxidation level. In both cultivars of S. rebaudiana plant, when compared to the plants in the control group under drought stress, while a decrease in leaf length was detected, the highest decrease was found in Yalova cultivar (25.7%). However, both cultivars maintained their water status under drought stress. While Fv/Fm value was not affected by drought in STF-4 cultivar, Yalova cultivar decreased compared to the control. In the amount of proline was a difference between the cultivars. While STF-4 cultivar under arid conditions no change was observed in the amount of proline, increase of 42.9% occurred in Yalova cultivar. On the other hand, drought stress significantly increased the lipid peroxidation level in leaves. While this increase was 41.2% in Yalova cultivar, it was 21.1% in STF-4 variety. Differential response to drought stress between the two cultivars, was observed in H2O2 content. The amount of H2O2 under drought stress, while decreased by 42.7% in Yalova cultivar it increased by 5.5% in STF-4 variety. As a result, in the light of the measured parameters the STF-4 cultivar of S. rebaudiana plant was revealed that more drought tolerant.

Keywords

Abiotic stress, Drought, Stevia rebaudiana, Stevia

Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri

Abstract

Kuraklık son yıllarda endişe verici bir şekilde artmakta olup tarımsal ürünlerin verimliliğini sınırlandırmaktadır. Bu durum, kurak koşullara dayanıklı bitkilerin tespit edilmesine yönelik araştırmaların önemini artırmıştır. Bu çalışmada, Stevia rebaudiana Bertoni bitkisine ait iki çeşidin (Yalova ve STF-4) kuraklık stresi altında fizyolojik ve biyokimyasal tepkileri araştırılmıştır. Bitkiler kontrollü sera koşullarında 3 ay boyunca yetiştirilmiş ve sonrasında 3 hafta boyunca kuraklığa maruz bırakılmıştır. Üç hafta sonunda hasat edilen bitkilerden yaprak uzunluğu, ozmotik potansiyel, nisbi su içeriği (RWC), klorofil floresansı (Fv/Fm), prolin miktarı, hidrojen peroksit (H2O2) miktarı ve lipid peroksidasyonu seviyesi ölçülmüştür. S. rebaudiana bitkisinin her iki çeşidinde de kuraklık stresi altında kontrol grubundaki bitkiler ile kıyaslandığında yaprak uzunluğunda azalma belirlenirken en çok azalma Yalova çeşidinde (%25,7) saptanmıştır. Bununla birlikte, her iki çeşit de kuraklık stresi altında su durumlarını korumuşlardır. Fv/Fm değeri STF-4 çeşidinde kuraklıktan etkilenmezken Yalova çeşidinde kontrole oranla düşüş göstermiştir. Prolin miktarında ise çeşitler arasında fark kaydedilmiştir. Kurak koşullar altında STF-4 çeşidinde prolin miktarında değişim gözlenmezken Yalova çeşidinde %42,9 artış meydana gelmiştir. Diğer taraftan, kuraklık stresi, yapraklardaki lipid peroksidasyon seviyesini önemli ölçüde arttırmıştır. Bu artış, Yalova çeşidinde %41,2 iken STF-4 çeşidinde %21,1 olarak belirlenmiştir. İki çeşit arasında kuraklık stresine karşı farklı tepki H2O2 içeriğinde gözlenmiştir. Kuraklık stresi altında H2O2 miktarı Yalova çeşidinde %42,7 oranında azalırken STF-4 çeşidinde %5,5 artmıştır. Sonuç olarak, S. rebaudiana bitkisinin STF-4 çeşidinin ölçülen parametreler ışığında kuraklığa daha toleranslı olduğu ortaya konulmuştur.

Keywords

Abiyotik stres, Kuraklık, Stevia rebaudiana, Şeker otu

Thanks

Bu çalışma Düzce Üniversitesi Bilimsel Araştırma Projeleri tarafından desteklenmiştir (Proje no: 2019.02.01.970). Yazar VY, 100/2000 YÖK doktora bursiyeridir.

References

[1] N. Pradhan, P. Singh, P. Dwivedi and D. K. Pandey, “Evaluation of sodium nitroprusside and putrescine on polyethylene glycol induced drought stress in Stevia rebaudiana Bertoni under in vitro condiition,” Industrial Crop and Products, vol. 154, 2020.
[2] J. Ahmad, I. Khan, R. Blundell, J. Azzopardi and M. F. Mahomoodally, “Stevia rebaudiana Bertoni.:an updated review of its health benefits, industrial applications and safety,” Trends in Food Science & Technology, vol. 100, pp. 177-189, 2020.
[3] N. H. Samsulrizal, K. S. Khadzran, S. HN.Shaarani, A. L. Noh, T. CM. Sundram, M. A. Naim and Z. Zainuddin, “De novo trancriptome dataset of Stevia rebaudiana accession MS007,” Data in Brief, vol. 28, 2020.
[4] C. Clemente, L. G. Angelini, R. Ascrizzi and S. Tavarini, “Stevia rebaudiana (Bertoni) as a multifunctional and sustainable crop for the Mediterranean climate,” Agriculture, vol. 11, no. 2, pp. 123, 2021.
[5] S. Hajihashemi and A. A. Ehsanpour, “Influence of exogenously applied paclobutrazol on some physiological traits and growth of Stevia rebaudiana under in vitro drought stress,” Biologia, vol. 68, no. 3, pp. 414-420, 2013.
[6] V. Peteliuk, L. Rybchuk, M. Bayliak, K. B. Storey and O. Lushchak, “Natural sweetener Stevia rebaudiana: functionalities, health benefits and potential risks,” EXCLI Journal, vol. 20, pp.1412-1430, 2021.
[7] Y. Sun, X. Xu, T. Zhang, Y. Yang, H. Tong and H. Yuan, “Comparative transcriptome analysis provides insights into steviol glycoside synthesis in stevia (Stevia rebaudiana Bertoni) leaves under nitrogen deficiency,” Plant Cell Reports, vol. 40, pp. 1709-1722, 2021.
[8] Z. Li, L. An, S. Zhang, Z. Shi, J. Bao, M. Tuerhong, M. Abudukeremu, J. Xu and Y. Guo, “Structural elucidation and immunomodulatory evalution of a polysaccaride from Stevia rebaudiana leaves,” Food Chemistry, vol. 364, pp. 130310, 2021.
[9] J. Wang, H. Zhao, Y. Wang, H. Lau, W. Zhou, C. Chen and S. Tan, “A review of stevia as a potential helathcare product: Up-to-date functional characteristics, administrative standarts and engineering techniques,” Trends in Food Science & Technology,’ vol. 103, pp. 264-281, 2020.
[10] S. Basharat, Z. Huang, M. Gong, X. Lv, A. Ahmed, I. Hussain, J. Li, G. Du and L. Liu, “A review on current conventional and biotechnical approaches to enhance biosynthesis of steviol glycosides in Stevia rebaudiana,” Chinese Journal of Chemical Engineering, vol. 30, pp. 92-104, 2021.

[11] E. S. Ibrahem, E. M. Ragheb, F. M. Yousef, M. F. Abdel-Azizand and B. A. Alghamdi, “Nutritional value, cytotoxic and antimicrobial activities of Stevia rebaudiana leaf extracts,” Journal of Biochemical Technology, vol. 11, no. 12, pp. 108-115, 2020.
[12] S. Yu-ming, H. Xiao-lei, Z. Ting, Y. Yong-heng, C. Xiao-fang, X. Xiao-yang and Y. Hai-yan, “Potassium deficiency inhibits steviol glycosides synthesis by limiting leaf sugar metabolism in stevia (Stevia rebaudiana Bertoni) plants,” Journal of Integrative Agriculture, vol. 20, no. 11, pp. 2932-2943, 2021.
[13] E. Yıldız Öztürk, A. Nalbantsoy, O. Tag and O. Yesil Celiktas, “A comporative study on extraction processes of Stevia rebaudiana leaves with emphasis on antioxidant, cytotoxic and nitric oxide inhibition activities,” Industrial Crops and Products, vol. 77, pp. 961-971, 2015.
[14] M. K. Warsi, S. M. Howladar and M. A. Alsharif, “Regulon: An overview of plant abiotic stress transcriptional regulatory system and role in transgenic plants,” Brazilian Journal of Biology, vol. 83, 2023.
[15] R. Guo, L. X. Shi, Y. Jiao, M. X. Li, X. L. Zhong, F. X. Gu, Q. Liu, X. Xia and H. Li, “Metabolic responses to drought stress in the tissues of drought-tolerant and drought-sensitive wheat genotype seedlings,” AOB Plants, vol. 10, 2018.
[16] S. S. Gill and N. Tuteja, “Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants,” Plant Physiology and Biochemistry, vol. 48, pp. 909-930, 2010.
[17] M. W. Oh and S. Komatsu, “Characterization of proteins in soybean roots under flooding and drought stresses,” Journal of Proteomics, vol. 114, pp. 161-181, 2015.
[18] Z. Kolenc, D. Vodnik, S. Mandelc, B. Javornik, D. Kastelec and A. Čerenak, “Hop (Humulus lupulus L.) response mechanisms in drought stress: Proteomic analysis with physiology,” Plant Physiology and Biochemistry, vol. 105, pp. 67-78, 2016.
[19] Z. Shu-han, X. Xue-feng, S. Yen-min, Z. Jun-lian and L. Chao-zhou, “Influence of drought hardening on the resistance physiology of potato seedlings under drought stress,” Journal of Integrative Agriculture, vol. 17, no. 2, pp. 336-347, 2018.
[20] X. Yang, M. Lu, Y. Wang, Y. Wang, Z. Liu and S. Chen, “Response mechanism of plants to drought stress,” Horticulturae, vol. 7, no. 3, pp. 50, 2021.
[21] Y. Zheng, Z. Xia, J. Wu and H. Ma, “Effects of repeated drought stress on the physiological characteristics and lipid metabolism of Bombax ceiba L. during subsequent drought and heat stresses,” BMC Plant Biology, vol. 21, 2021.
[22] M. Karimi, A. Ahmadi, J. Hashemi, A. Abbasi, S. Tavarini, A. Pompeiano, L. Guglielminetti and L. G. Angelini, “The positive role of steviol glycosides in stevia (Stevia rebaudiana Bertoni) under drought stress condition,” Official Journal of the Societa Botanica Italiana, vol. 150, no. 6, pp. 1321-1331, 2016.
[23] S. Backhaus, J. Kreyling, K. Grant, C. Beierkuhnlein, J. Walter and A. Jentsch, “Recurrent mild drought events increase resistance toward extreme drought stress,” Ecosystems, vol. 17, pp. 1068-1081, 2014.
[24] H. A. Alhaithloul, M. H. Soliman, K. L. Ameta, M. A. El-Esawi and A. Elkelish, “Changes in ecophysiology, osmolytes, and secondary metabolites of the medicinal plants of Mentha piperita and Catharanthus roseus subjected to drought and heat stress,” Biomolecules, vol. 10, no. 1, 2020.
[25] P. García-Caparrós, M. J. Romeo, A. Llanderal, P. Cermeño, M. T. Lao and M. L. Segura, “Effects of drought stress on biomass, essential oil content, nutritional parameters, and costs of production in six Lamiaceae species,” Water, vol. 11, 2019.
[26] A. G. Pirbalouti, F. Malekpoor, A. Salimi, A. Golparvar and B. Hamedi, “Effects of foliar of the application chitosan and reduced irrigation on essential oil yield, total phenol content and antioxidant activity of extracts from green and purple basil,” Acta Sci. Pol. Hortorum Cultus, vol. 16, no. 6, pp. 177-186, 2017.
[27] A. Mahdavi, P. Moradi and A. Mastinu, “Variation in terpene profiles of Thymus vulgaris in water deficit stress response,” Molecules, vol. 25, no. 5, 2020.
[28] R. E. Smart and G. E. Bingham, “Rapid estimates of relative water content,” Plant Physiology, vol. 53, pp. 258–260, 1974.
[29] A. Santa-Cruz, M. M. Martinez-Rodriguez, F. Perez-Alfocea, R. Romero-Aranda, and M. C. Bolarin, “The rootstock effect on the tomato salinity response depends on the shoot genotype,” Plant Science, vol. 162, pp. 825–831, 2002.
[30] L. S. Bates, R. P. Waldren, and I. D. Teare, “Rapid determination of free proline for water stress studies,” Plant Soil, vol. 39, pp. 205–207, 1973.
[31] J. Liu, B. Lu, and A. L. Xun, “An improved method for the determination of hydrogen peroxide in leaves,” Progress in Biochemistry and Biophysics, vol. 27, pp. 548–551, 2000.
[32] K. V. Madhava Rao and T. V. S. Sresty, “Antioxidative parameters in the seedlings of Pigeonpea (Cajanus cajan L. Millspaugh) in response to Zn and Ni stresses,” Plant Science, vol. 157, pp. 113–128, 2000.
[33] Z. Ahmad, S. Anjum, E. A. Waraich, M. A. Ayub, T. Ahmad, R. M. S. Tariq, R. Ahmad and M. A. Iqbal, “Growth, physiology, and biochemical activities of plant responses with foliar potassium application under drought stress – a review,” Journal of Plant Nutrition, vol. 41, no. 13, pp. 1734-1743, 2018.
[34] S. Hajihashemi and J. M. C. Geuns, “Gene transcription and steviol glycoside accumulation in Stevia rebaudiana under polyethylene glycol-induceddrought stress in greenhouse cultivation,” FEBS Open Bio, vol. 6, pp. 937-944, 2016.
[35] R. Ayrancı, “Farklı kuraklık tiplerinde ekmeklik buğday genotiplerinin fizyolojik, morfolojik, verim ve kalite özellikleri yönüyle ıslahta kullanılabilecek uygun parametrelerin belirlenmesi,” Doktora tezi, Tarla Bitkileri, Selçuk Üniversitesi, Konya, Türkiye, 2012.
[36] B. Jiang, P. Wang, S. Zhuang, M. Li, Z. Li and Z. Gong, “Detection of maize drought based on texture and morphological features,” Computers and Electronics in Agriculture, vol. 151, pp. 50-60, 2018.
[37] H. Aydın, H. Torun ve E. Eroğlu, “Cephalaria duzceënsis N. Aksoy & R. S. Göktürk ve Seseli resinosum Freyn & Sint. endemik taksonlarının morfolojik ve fizyolojik özellikleri ile bitkilendirmede kullanılabilme potansiyelleri,” D.Ü. Ormancılık Dergisi, c. 16, s. 2, ss. 89-104, 2020.
[38] Md. R. Molla, Md. M. Rohman, M. B. Monsur, M. Hasanuzzaman and L. Hassan, “Screening and assessment of selected Chilli (Capsicum annuum L.) genotypes for drought tolerance at seedling stage,” Phyton-International Journal of Experimental Botany, vol. 90, no. 5, 2021.
[39] S. Kıran, F. Özkay, Ş. Ellialtıoğlu ve Ş. Kuşvuran, “Kuraklık stresi uygulanan kavun genotiplerinde bazı fizyolojik değişimler üzerine araştırmalar,” Toprak Su Dergisi, c. 3, s. 1, ss. 53-58, 2014.
[40] H. Y. Daşgan, M. Kılınç, S. Dere ve B. İkiz, “Çukurova ekolojik koşullarına uygun bazı karpuz çeşitlerinin kuraklığa tolerans seviyelerinin belirlenmesi,” Uluslararası Tarım ve Yaban Hayatı Bilimleri Dergisi, c. 7, s. 3, ss. 388-403, 2021.
[41] S. Hajihashemi and A. Sofo, “The effect of polyethylene glycol-induced drought stress on photosynthesis, carbohydrates and cell membrane in Stevia rebaudiana grown in greenhouse,” Acta Physiologiae Plantarum, vol. 40, 2018.
[42] M. Ashraf and M. Foolad, “Roles of glycine betaine and proline in improving plant abiotic stress resistance,” Environmental and Experimental Botany, vol. 59, no. 2, pp. 206-216, 2007.
[43] N. Verbruggen and C. Hermans, “Proline accumulation in plants: a review,” Amino Acids, vol. 35, pp.753-759, 2008.
[44] D. C. Dien, T. Mochizuki and T. Yamakawa, “Effect of various drought stresses and subsequent recovery on proline, total soluble sugar and starch metabolisms in Rice (Oryza sativa L.) varieties,” Plant Production Science, vol. 22, no. 4, pp. 530-545, 2019.
[45] C. Y. Zhao, J. H. Si, Q. Feng, T. F. Yu, H. Luo and J. Qin, “Ecophysiological responses to drought stress in Populus euphratica,” Sciences in Cold and Arid Regions, vol. 13, no. 4, pp. 326-336, 2021.
[46] F. Nadali, H. R. Asghari, H. Abbasdokht, V. Dorostkar and M. Bagheri, “Improved Quinoa growth, physiological response, and yield by hydropriming under drought stress conditions,” Gesunde Pflanzen, vol. 73, no. 1, pp. 53-66, 2021.
[47] Z. Adamipour, M. Khosh-Khui, H. Salehi, H. Razi, A. Karami and A. Moghadam, “Metabolic and genes expression analyses involved in proline metabolism of two rose species under drought stress,” Plant Physiology and Biochemistry, vol. 155, pp. 105-113, 2020.
[48] L. Zhou, X. Tian, B. Cui and A. Hussain, “Physiological and biochemical responses of invasive species Cenchrus pauciflorus benth to drought stress,” Sustainability, vol. 13, no. 11, 2021.
[49] M. Rehman, S. Syed, Q. Ali, Z. Haider, S. Kamal and M. Azeem, “Morphological and biochemical investigations of selected wheat (Triticum aestivum L.) cultivars for the drought tolerance potential: photosynthetic pigments and lipid peroxidation,” Fresenius Environmental Bulletin, vol. 30, no. 6, pp. 6155-6164, 2021.
[50] N. Azad, M. Rezayian, H. Hassanpour, V. Niknam and H. Ebrahimzadeh, “Physiological mechanism of salicylic acid in Mentha pulegium L. under salinity and drought stress,” Brazilian Journal of Botany, vol. 44, pp. 359-369, 2021.
[51] T. A. Siswoyo, L. S. Arum, B. R. L. Sanjava and Z. S. Aisyah, “The growth responses and antioxidant capabilities of melinjo (Gnetum gnemon L.) in different durations of drought stress,” Annals of Agricultural Sciences, vol. 66, no. 1, pp. 81-86, 2021.
[52] S. Caşka Kılıçarslan, E. Yıldırım, M. Ekinci ve R. Kul, “Kuraklık stresinin fasulyede bitki gelişimi, bazı fizyolojik ve biyokimyasal özellikler üzerine etkisi,” Erciyes Üniversitesi Fen Bilimleri Enstitüsü Dergisi, c. 36, s. 2, 2020.
[53] B. Chang, K. Ma, Z. Lu, J. Lu, J. Cui, L. Wang and B. Jin, “Physiological, Transcriptomic and metabolic responses of Ginkgo biloba L. to drought, salt and heat stress,” Biomolecules, vol. 10, no. 12, 2020.
[54] K. Jothimani and D. Arulbalachandran, “Physiological and biochemical studies of black gram (Vigna mungo (L.) Hepper) under polyethylene glycol induced drought stress,” Biocatalysis and Agricultural Biotechnology, vol. 29, 2020.
[55] S. Sundararajan, R. Shanmugam, V. Rajendran, H. P. Sivakumar and S. Ramalingam, “Sodium nitroprusside and putrescine mitigate PEG induced drought stress in seedlings of Solanum lycopersicum,” Journal of Soil Science and Plant Nutrition, 2021, doi: 10.1007/s42729-021-00710-x.

Details

Primary Language

Turkish

Subjects

Engineering

Journal Section

Research Article

Authors

Vesile Yalçın
0000-0003-1293-732X
Türkiye

Hülya Torun ^*
0000-0002-1118-5130
Türkiye

Engin Eroğlu
0000-0002-1777-8375
Türkiye

Elmas Ülkühan Usta
0000-0001-8877-1106
Türkiye

Publication Date

July 31, 2022

Submission Date

April 28, 2022

Acceptance Date

May 12, 2022

Published in Issue

Year 2022 Volume: 10 Number: 3

DOI

https://doi.org/10.29130/dubited.1109502

IZ

https://izlik.org/JA26BE96SS

APA

Yalçın, V., Torun, H., Eroğlu, E., & Usta, E. Ü. (2022). Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri. Duzce University Journal of Science and Technology, 10(3), 1165-1176. https://doi.org/10.29130/dubited.1109502

AMA

1.Yalçın V, Torun H, Eroğlu E, Usta EÜ. Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri. DUBİTED. 2022;10(3):1165-1176. doi:10.29130/dubited.1109502

Chicago

Yalçın, Vesile, Hülya Torun, Engin Eroğlu, and Elmas Ülkühan Usta. 2022. “Şeker Otu (Stevia Rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik Ve Biyokimyasal Etkileri”. Duzce University Journal of Science and Technology 10 (3): 1165-76. https://doi.org/10.29130/dubited.1109502.

EndNote

Yalçın V, Torun H, Eroğlu E, Usta EÜ (July 1, 2022) Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri. Duzce University Journal of Science and Technology 10 3 1165–1176.

IEEE

[1]V. Yalçın, H. Torun, E. Eroğlu, and E. Ü. Usta, “Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri”, DUBİTED, vol. 10, no. 3, pp. 1165–1176, July 2022, doi: 10.29130/dubited.1109502.

ISNAD

Yalçın, Vesile - Torun, Hülya - Eroğlu, Engin - Usta, Elmas Ülkühan. “Şeker Otu (Stevia Rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik Ve Biyokimyasal Etkileri”. Duzce University Journal of Science and Technology 10/3 (July 1, 2022): 1165-1176. https://doi.org/10.29130/dubited.1109502.

JAMA

1.Yalçın V, Torun H, Eroğlu E, Usta EÜ. Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri. DUBİTED. 2022;10:1165–1176.

MLA

Yalçın, Vesile, et al. “Şeker Otu (Stevia Rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik Ve Biyokimyasal Etkileri”. Duzce University Journal of Science and Technology, vol. 10, no. 3, July 2022, pp. 1165-76, doi:10.29130/dubited.1109502.

Vancouver

1.Vesile Yalçın, Hülya Torun, Engin Eroğlu, Elmas Ülkühan Usta. Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri. DUBİTED. 2022 Jul. 1;10(3):1165-76. doi:10.29130/dubited.1109502

Cited By

Prolin ve Stres Toleransındaki Önemi

Türkiye Tarımsal Araştırmalar Dergisi

https://doi.org/10.19159/tutad.1699873