The Genetics of Pandan-Like Fragrance, 2-Acetyl-1-Pyrroline, in Crops

Prakit Somta, Kuswanto Kuswanto, Peerasak Srinives


The main advantages of pandan (Pandanus amaryllifolius (Roxb.) is the fresh leaves which mainly used for the pleasant fragrance in cuisine. 2-acytile-1-pyrroline (2AP) (also known as 1-(3,4-dihydro-2H-pyrrol-5yl)ethanone) is the principle volatile chemical responsible for the fragrance in pandan.  2AP was identified for the first time from the cooked rice. Many cultivars of certain crops also produce pandan-like fragrance/2AP including rice (Oryza sativa L.), sorghum (Sorghum bicolor (L.) Moench), mungbean (Vigna radiata (L.) Wilczek), soybean (Glycine max (L.) Merr.), coconut (Cocos nucifera L.), cucumber (Cucumis sativus L.), wax gourd (Benincasa hispida), and taro (Colocasia esculenta (L.) Schott). The fragrant crop varieties command higher price than non-fragrant cultivars. Breeding for fragrance is a main goal in breeding programs in these crops. Although genetics studies revealed that the presence of fragrance in crops is monogenic trait and that mutation(s) resulting in null or reduced function of betaine aldehyde dehydrogenase 2 (BADH2)/amino aldehyde dehydrogenase (AADH) causes production of 2AP, the level of the fragrance is quantitative in nature. In this paper, we review and discuss the genetic controls of the fragrance in some crops.


2AP; fragrant cultivar; genetic control; pandan-like fragrance

Full Text:



Ahn, S. N., Bollich, C. N., & Tanksley, S. D. (1992). RFLP tagging of a gene for aroma in rice. Theoretical and Applied Genetics, 84(7–8), 825–828. crossref

Amarawathi, Y., Singh, R., Singh, A. K., Singh, V. P., Mohapatra, T., Sharma, T. R., & Singh, N. K. (2008). Mapping of quantitative trait loci for basmati quality traits in rice (Oryza sativa L.). Molecular Breeding, 21(1), 49–65. crossref

Arikit, S., Yoshihashi, T., & Vanavichit, A. (2007). Os2AP, the aromatic gene controlling the biosynthetic switch of 2-acetyl-1-pyrroline and gamma aminobutyric acid (GABA) in rice. In BioAsia 2007: The 6th Asian Crop Science Association Conference and The 2nd International Conference on Rice for the Future (p. 162). Bangkok, TH: Queen Sirikit National Convention Center. Retrieved from pdf

Arikit, S., Yoshihashi, T., Wanchana, S., Uyen, T. T., Huong, N. T. T., Wongpornchai, S., & Vanavichit, A. (2011). Deficiency in the amino aldehyde dehydrogenase encoded by GmAMADH2, the homologue of rice Os2AP, enhances 2-acetyl-1-pyrroline biosynthesis in soybeans (Glycine max L.). Plant Biotechnology Journal, 9(1), 75–87. crossref

Berner, D. K., & Hoff, B. J. (1986). Inheritance of scent in American long grain rice. Crop Science, 26(5), 876–878. crossref

Bradbury, L. M. T., Fitzgerald, T. L., Henry, R. J., Jin, Q., & Waters, D. L. E. (2005). The gene for fragrance in rice. Plant Biotechnology Journal, 3(3), 363–370. crossref

Bradbury, L. M. T., Gillies, S. A., Brushett, D. J., Waters, D. L. E., & Henry, R. J. (2008). Inactivation of an aminoaldehyde dehydrogenase is responsible for fragrance in rice. Plant Molecular Biology, 68(4–5), 439–449. crossref

Buttery, R. G., Juliano, B. O., & Ling, L. C. (1983). Identification of rice aroma compound 2-acetyl-1-pyrroline in pandan leaves. Chemistry & Industry, 23, 478–479.

Buttery, R. G., Ling, L. C., Juliano, B., & Turnbaugh, J. G. (1983). Cooked rice aroma and 2-acetyl-1-pyrroline. Journal of Agricultural and Food Chemistry, 31(4), 823–826. crossref

Chakravarty, A. K. (1948). A genetical study of the botanical characters in rice. Oryza Sativa, 50–57. Retrieved from genetical study of botanical characters in riceOryza sativa L&author=A. K.. Chakravarty&journal=Bull. Bot. Soc. Bengal&volume=2&pages=50-58&publication_year=1948

Chen, S., Yang, Y., Shi, W., Ji, Q., He, F., Zhang, Z., … Xu, M. (2008). BADH2, encoding betaine aldehyde dehydrogenase, inhibits the biosynthesis of 2-acetyl-1-pyrroline, a major component in rice fragrance. The Plant Cell, 20(7), 1850–1861. crossref

Chomcalow, N. (1999). Coconut varieties in Thailand. AU Journal of Technology, 3(1), 19–30. Retrieved from website

Daygon, V. D., Calingacion, M., Forster, L. C., De Voss, J. J., Schwartz, B. D., Ovenden, B., … Fitzgerald, M. A. (2017). Metabolomics and genomics combine to unravel the pathway for the presence of fragrance in rice. Scientific Reports, 7, 8767. crossref

de Wilde, W. J. J. O., & Duyfjes, B. E. E. (2010). Cucumis sativus L. forma hardwickii (Royle) W.J. de Wilde & Duyfjes and feral forma sativus. Thai Forest Bulletin (Botany), 38, 98–107. Retrieved from website

Dhulappanavar, C. V. (1976). Inheritance of scent in rice. Euphytica, 25(1), 659–662. crossref

Fitzgerald, M. A., Sackville Hamilton, N. R., Calingacion, M. N., Verhoeven, H. A., & Butardo, V. M. (2008). Is there a second fragrance gene in rice? Plant Biotechnology Journal, 6(4), 416–423. crossref

Fushimi, T., & Masuda, R. (2001). 2-acetyl-1-pyrroline concentration of the aromatic vegetable soybean "Dadacha-mame". In T. A. Lumpkin & S. Shanmugasundaram (Eds.). Paper presented at Proceedings of the 2nd International Vegetable Soybean Conference, Tacoma (39p.). Washington, USA: Washington State University. Retrieved from website

Ghose, R. L. M., & Butany, W. T. (1952). Studies on the inheritance of some characters in rice (Oryza sativa L.). Indian Journal of Genetics and Plant Breeding, 12(1), 25-30.

Gunn, B. F., Baudouin, L., & Olsen, K. M. (2011). Independent origins of cultivated coconut (Cocos nucifera L.) in the old world tropics. PLoS ONE, 6(6), e21143. crossref

Hinge, V. R., Patil, H. B., & Nadaf, A. B. (2016a). Aroma volatile analyses and 2AP characterization at various developmental stages in Basmati and Non-Basmati scented rice (Oryza sativa L.) cultivars. Rice, 9, 38. crossref

Hinge, V., Patil, H., & Nadaf, A. (2016b). Comparative characterization of aroma volatiles and related gene expression analysis at vegetative and mature stages in basmati and non-basmati rice (Oryza sativa L.) cultivars. Applied Biochemistry and Biotechnology, 178(4), 619–639. crossref

Huang, S., Li, R., Zhang, Z., Li, L., Gu, X., Fan, W., … Li, S. (2009). The genome of the cucumber, Cucumis sativus L. Nature Genetics, 41, 1275–1281. crossref

Huang, T. C., Teng, C. S., Chang, J. L., Chuang, H. S., Ho, C. T., & Wu, M. L. (2008). Biosynthetic mechanism of 2-acetyl-1-pyrroline and its relationship with Delta1-pyrroline-5-carboxylic acid and methylglyoxal in aromatic rice (Oryza sativa L.) callus. Journal of Agricultural and Food Chemistry, 56(16), 7399–7404. crossref

Jodon, N. E. (1944). The inheritance of flower fragrance and other characters in rice. Journal of the American Society of Agronomy, 36(10), 844-848. Retrieved from pdf

Juwattanasomran, R., Somta, P., Chankaew, S., Shimizu, T., Wongpornchai, S., Kaga, A., & Srinives, P. (2011). A SNP in GmBADH2 gene associates with fragrance in vegetable soybean variety “Kaori” and SNAP marker development for the fragrance. Theoretical and Applied Genetics, 122(3), 533–541. crossref

Juwattanasomran, R., Somta, P., Kaga, A., Chankaew, S., Shimizu, T., Sorajjapinun, W., & Srinives, P. (2012). Identification of a new fragrance allele in soybean and development of its functional marker. Molecular Breeding, 29(1), 13–21. crossref

Kadam, B. S., & Patankar, V. K. (1938). Inheritance of aroma in rice. Chronica Botanica, 4, 32.

Kirch, H.-H., Schlingensiepen, S., Kotchoni, S., Sunkar, R., & Bartels, D. (2005). Detailed expression analysis of selected genes of the aldehyde dehydrogenase (ALDH) gene superfamily in Arabidopsis thaliana. Plant Molecular Biology, 57(3), 315–332. crossref

Kottur, G. L. (1919). Classification and description of the jowars of the Bombay Karnataka. Bombay Department Agricultural Bulletin, 92, p. 16.

Kovach, M. J., Calingacion, M. N., Fitzgerald, M. A., & McCouch, S. R. (2009). The origin and evolution of fragrance in rice (Oryza sativa L.). Proceedings of the National Academy of Sciences USA, 106(34), 14444–14449. crossref

Krisanapook, K., Jaroonchon, N., & Imsabai, W. (2016). Physiological traits and 2-acetyl-1-pyrroline development of aromatic coconut fruit. Acta Horticulturae, 1129, 79–84. crossref

Lorieux, M., Petrov, M., Huang, N., Guiderdoni, E., & Ghesquière, A. (1996). Aroma in rice: Genetic analysis of a quantitative trait. Theoretical and Applied Genetics, 93(7), 1145–1151. crossref

Luckanatinvong, V., & Sornkeaw, P. (2011). Quality of blanched aromatic young coconut fruits for export. Agricultural Science Journal, 42(1(Suppl.)), 147–150. Retrieved from pdf

Mathure, S. V., Jawali, N., Thengane, R. J., & Nadaf, A. B. (2014). Comparative quantitative analysis of headspace volatiles and their association with BADH2 marker in non-basmati scented, basmati and non-scented rice (Oryza sativa L.) cultivars of India. Food Chemistry, 142, 383–391. crossref

Murty, D. S., Nicodemus, K. D., & House, L. R. (1982). Inheritance of basmati and dimpled seed in sorghum. Crop Science, 22(5), 1080–1082. crossref

Nagaraju, M., Chaudhary, D., & Balakrishna-Rao, M. J. (1975). Simple technique to identify scent in rice and inheritance pattern of scent. Current Science, 44, 599. Retrieved from website

Niu, X., Tang, W., Huang, W., Ren, G., Wang, Q., Luo, D., … Liu, Y. (2008). RNAi-directed downregulation of OsBADH2 results in aroma (2-acetyl-1-pyrroline) production in rice (Oryza sativa L.). BMC Plant Biology, 8, 100. crossref

Pachauri, V., Mishra, V., Mishra, P., Singh, A. K., Singh, S., Singh, R., & Singh, N. K. (2014). Identification of candidate genes for rice grain aroma by combining QTL mapping and transcriptome profiling approaches. Cereal Research Communications, 42(3), 376–388. crossref

Pinson, S. R. M. (1994). Inheritance of aroma in six rice cultivars. Crop Science, 34(5), 1151–1157. crossref

Pooprasert, A., Imsabai, W., Arikit, S., & Boonruangrod, R. (2015). Study on xenia effect on aroma of aromatic coconut (Cocos nucifera L.). Paper presented at The 15th National Horticulture Congress, Thailand. Thailand: Department of Plant Science, Faculty of Natural Resources, Prince of Songkhla University. Retrieved from pdf

Pramnoi, P., Somta, P., Chankaew, S., Juwattanasomran, R., & Srinives, P. (2013). A single recessive gene controls fragrance in cucumber (Cucumis sativus L.). Journal of Genetics, 92(1), 147–149. crossref

Rao, K. E. P., & Murty, D. S. (1979). A Basmati (scented) sorghum from Madhya Pradesh. Current Science, 20, 824–825.

Reddy, P. R., & Sathyanarayanaiah, K. (1980). Inheritance of aroma in rice. Indian Journal of Genetics and Plant Breeding, 40, 327-329.

Richharia, R. H., Mishra, B., & Kulkami, V. A. (1965). Studies in the world genetic stock of rice. IV. Distribution of scented rice. Oryza, 2, 57-59.

Saensuk, C., Wanchana, S., Choowongkomon, K., Wongpornchai, S., Kraithong, T., Imsabai, W., … Arikit, S. (2016). De novo transcriptome assembly and identification of the gene conferring a “pandan-like” aroma in coconut (Cocos nucifera L.). Plant Science, 252, 324–334. crossref

Shan, Q., Zhang, Y., Chen, K., Zhang, K., &Gao, C. (2015). Creation of fragrant rice by targeted knockout of the OsBADH2 gene using TALEN technology. Plant Biotechnology Journal, 13(6), 791–800. crossref

Shi, W., Yang, Y., Chen, S., & Xu, M. (2008). Discovery of a new fragrance allele and the development of functional markers for the breeding of fragrant rice varieties. Molecular Breeding, 22(2), 185–192. crossref

Singh, A., Singh, P. K., Singh, R., Pandit, A., Mahato, A. K., Gupta, D. K., … Sharma, T. R. (2010). SNP haplotypes of the BADH1 gene and their association with aroma in rice (Oryza sativa L.). Molecular Breeding, 26(2), 325–338. crossref

Singh, R., Singh, A. K., Sharma, T. R., Singh, A., & Singh, N. K. (2007). Fine mapping of aroma QTLs in basmati rice (Oryza sativa L) on chromosomes 3, 4 and 8. Journal of Plant Biochemistry and Biotechnology, 16(2), 75–82. crossref

Sood, B. C., & Siddiq, E. A. (1978). A rapid technique for scent determination in rice. Indian Journal of Genetics and Plant Breeding, 38, 268–271. Retrieved from website

Tripathi, R. S., & Rao, M. J. B. K. (1979). Inheritance and linkage relationship of scent in rice. Euphytica, 28(2), 319–323. crossref

Tsuzuki, E., & Shimokawa, E. (1990). Inheritance of aroma in rice. Euphytica, 46(2), 157–159. crossref

Tylichová, M., Kopečný, D., Snégaroff, J., & Šebela, M. (2007). Aminoaldehyde dehydrogenases: has the time now come for new interesting discoveries? Current Topics in Plant Biology, 8, 45-70. Retrieved from website

Vanavichit, A., Kamolsukyurnyong, W., Wanchana, S., Wongpornchai, S., Ruengphayak, S., Toojinda, T.,& Tragoonrung, S. (2004). Discovering genes for rice grain aroma. In S. Vanavichit (ed.). Paper presented at Proceedings of the 1st International Conference on Rice for the Future (pp.71-80). Kasetsart University: Bangkok, TH.

Vongvanrungruang, A., Mongkolsiriwatana, C., Boonkaew, T., Sawatdichaikul, O., Srikulnath, K., & Peyachoknagul, S. (2016). Single base substitution causing the fragrant phenotype and development of a type-specific marker in aromatic coconut (Cocos nucifera). Genetics and Molecular Research, 15(3), gmr.15038748. crossref

Wanchana, S. (2005). Identification of genes controlling grain aroma and amylose content for positional cloning and marker-assisted selection program in rice (Oryza sativa L.). Graduate School, Kasetsart University, Bangkok, TH. Retrieved from website

Wanchana, S., Kamolsukyurnyong, W., Ruengphayak, S., Toojinda, T., Tragoonrung, S.,& Vanavichit, A. (2004). Enhancing 2-acetyl-1-pyrroline synthesis in rice leaves by RNAi-mediated suppression of Os2AP converts non-aromatic to aromatic rice (Oryza sativa L.). In S. Vanavichit (ed.). Paper presented at Proceedings of the 1st International Conference on Rice for the Future (p. 105). Kasetsart University: Bangkok, TH.

Wongpornchai, S., Sriseadka, T., & Choonvisase, S. (2003). Identification and quantitation of the rice aroma compound, 2-acetyl-1-pyrroline, in bread flowers (Vallaris glabra Ktze). Journal of Agricultural and Food Chemistry, 51(2), 457–462. crossref

World Vegetable Center. (2003). AVRDC progress report 2002. Retrieved from pdf

Wu, M. L., Chou, K. L., Wu, C. R., Chen, J. K., & Huang, T. C. (2009). Characterization and the possible formation fechanism of 2-acetyl-1-pyrroline in aromatic vegetable soybean (Glycine max L.). Journal of Food Science, 74(5), S192–S197. crossref

Yoshihashi, T., Huong, N. T. T., & Inatomi, H. (2002). Precursors of 2-acetyl-1-pyrroline, a potent flavor compound of an aromatic rice variety. Journal of Agricultural and Food Chemistry, 50(7), 2001–2004. crossref

Yundaeng, C., Somta, P., Tangphatsornruang, S., Chankaew, S., & Srinives, P. (2015). A single base substitution in BADH/AMADH is responsible for fragrance in cucumber (Cucumis sativus L.), and development of SNAP markers for the fragrance. Theoretical and Applied Genetics, 128(9), 1881–1892. crossref

Yundaeng, C., Somta, P., Tangphatsornruang, S., Wongpornchai, S., & Srinives, P. (2013). Gene discovery and functional marker development for fragrance in sorghum (Sorghum bicolor (L.) Moench). Theoretical and Applied Genetics, 126(11), 2897–2906. crossref


Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.