Abstract
To feed an estimated world population of 8.9 billion by 2050, strategies for increasing grain production must be developed. Several agronomically important traits for increasing yield, such as plant height, grain number, and leaf erectness, have recently been characterized in rice (Oryza sativa L.). These traits are regulated primarily by three phytohormones: gibberellins, cytokinins, and brassinosteroids. The control of biosynthesis and degradation of these key phytohormones is discussed in terms of its importance for normal plant growth. Genes involved in the biosynthesis and regulation of these phytohormones can be used to develop effective strategies to increase grain yield. Genetic manipulation of phytohormone-related gene expression is thus a practical strategy to generate high-yielding transgenic plants through the modification of levels and profile of endogenous phytohormones.
Similar content being viewed by others
References
Ashikari M, Sakakibara H, Lin S, Yamamoto T, Takashi T, Nishimura A, Angeles ER, Qian Q, Kitano H, Matsuoka M (2005) Cytokinin oxidase regulates rice grain production. Science 309:741–745
Coles JP, Phillips AL, Croker SJ, Garcia-Lepe R, Lewis MJ, Hedden P (1999) Modification of gibberellin production and plant development in Arabidopsis by sense and antisense expression of gibberellin 20-oxidase genes. Plant J 17:547–556
Conway G, Toenniessen G (1999) Feeding the world in the twenty-first century. Nature 402:C55–C58
Fu X, Sudhakar D, Peng J, Richards DE, Christou P, Harberd NP (2001) Expression of Arabidopsis GAI in transgenic rice represses multiple gibberellin responses. Plant Cell 13:1791–1802
Gale MD, Devos KM (1998) Comparative genetics in the grasses. Proc Natl Acad Sci USA 95:1971–1974
Hedden P, Phillips AL (2000a) Gibberellin metabolism:new insights revealed by the genes. Trends Plant Sci 5:523–530
Hedden P, Phillips AL (2000b) Manipulation of hormone biosynthetic genes in transgenic plants. Curr Opin Biotech 11:130–137
Hong Z, Ueguchi-Tanaka M, Fujioka S, Takatsuto S, Yoshida S, Hasegawa Y, Ashikari M, Kitano H, Matsuoka M (2005) The rice brassinosteroid-deficient dwarf2 mutant, defective in the rice ortholog of Arabidopsis DIMINUTO/DWARF1, is rescued by the endogenously accumulated alternative bioactive brassinosteroid, dolichosterone. Plant Cell 17:2243–2254
Hong Z, Ueguchi-Tanaka M, Umemura K, Uozu S, Fujioka S, Takatsuto S, Yoshida S, Ashikari M, Kitano H, Matsuoka M (2003) A rice brassinosteroid-deficient mutant, ebisu dwarf (d2), is caused by a loss of function of a new member of cytochrome P450. Plant Cell 15:2900–2910
Horton P (2000). Prospects for crop improvement through the genetic manipulation of photosynthesis: morphological and biochemical aspects of light capture. J Exp Bot 51:475–485
Ikeda A, Ueguchi-Tanaka M, Sonoda Y, Kitano H, Koshioka M, Futsuhara Y, Matsuoka M, Yamaguchi J (2001) slender rice, a constitutive gibberellin response mutant, is caused by a null mutation of the SLR1 gene, an ortholog of the height-regulating gene GAI/RGA/RHT/D8. Plant Cell 13:999–1010
Itoh H, Ueguchi-Tanaka M, Sakamoto T, Kayano T, Tanaka H, Ashikari M, Matsuoka M (2002) Modification of rice plant height by suppressing the height-controlling gene, D18, in rice. Breed Sci 52: 215–218
Itoh H, Ueguchi-Tanaka M, Sentoku N, Kitano H, Matsuoka M, Kobayashi M (2001) Cloning and functional analysis of gibberellin 3β-hydroxylase genes that are differently expressed during the growth of rice. Proc Natl Acad Sci USA 98:8909–8914
Khush GS (1999) Green revolution: preparing for the 21st century. Genome 42:646–655
Mann CC (1999) Crop scientists seek a new revolution. Science 283:310–314
Mok MC (1994) Cytokinins and plant development—an overview. In: Mok DWS, Mok MC (eds). Cytokinins—chemistry, activity, and function. CRC Press, Boca Raton, FL, pp 155–166
Mok DW, Mok MC (2001) Cytokinin metabolism and action. Annu Rev Plant Physiol Plant Mol Biol 52:89–118
Morinaka Y, Sakamoto T, Inukai Y, Agetsuma M, Kitano H, Ashikari M, Matsuoka M (2006) Morphological alteration caused by brassinosteroid insensitivity increases the biomass and grain production of rice. Plant Physiology 141:in press
Neff MM, Nguyen SM, Malancharuvil EJ, Fujioka S, Noguchi T, Seto H, Tsubuki M, Honda T, Takatsuto S, Yoshida S, Chory J (1999) BAS1: A gene regulating brassinosteroid levels and light responsiveness in Arabidopsis. Proc Natl Acad Sci USA 96:15316–15323
Peng J, Richards DE, Hartley NM, Murphy GP, Devos KM, Flintham JE, Beales J, Fish LJ, Worland AJ, Pelica F, Sudhakar D, Christou P, Snape JW, Gale MD, Harberd NP (1999) ‘Green revolution’ genes encode mutant gibberellin response modulators. Nature 400:256–261
Sakamoto T, Kobayashi M, Itoh H, Tagiri A, Kayano T, Tanaka H, Iwahori S, Matsuoka M (2001) Expression of a gibberellin 2-oxidase gene around the shoot apex is related to phase transition in rice. Plant Physiol 125:1508–1516
Sakamoto T, Morinaka Y, Ishiyama K, Kobayashi M, Itoh H, Kayano T, Iwahori S, Matsuoka M, Tanaka H (2003) Genetic manipulation of gibberellin metabolism in transgenic rice. Nat Biotechnol 21:909–913
Sakamoto T, Morinaka Y, Ohnishi T, Sunohara H, Fujioka S, Ueguchi-Tanaka M, Mizutani M, Sakata K, Takatsuto S, Yoshida S, Tanaka H, Kitano H, Matsuoka M (2006) Erect leaves caused by brassinosteroid deficiency increase biomass production and grain yield in rice. Nat Biotechnol 24:105–109
Sasaki A, Ashikari M, Ueguchi-Tanaka M, Itoh H, Nishimura A, Swapan D, Ishiyama K, Saito T, Kobayashi M, Khush GS, Kitano H, Matsuoka M (2002) Green revolution:a mutant gibberellin-synthesis gene in rice. Nature 416:701–702
Sasaki T, Matsumoto T, Antonio BA, Nagamura Y (2005) From mapping to sequencing, post-sequencing and beyond. Plant Cell Physiol 46:3–13
Sinclair TR, Sheehy JE (1999) Erect leaves and photosynthesis in rice. Science 283:1456–1457
Tanabe S, Ashikari M, Fujioka S, Takatsuto S, Yoshida S, Yano M, Yoshimura A, Kitano H, Matsuoka M, Fujisawa Y, Kato H, Iwasaki Y (2005) A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant, dwarf11, with reduced seed length. Plant Cell 17:776–790
Werner T, Motyka V, Laucou V, Smets R, Onckelen H, Schmülling T (2003) Cytokinin-deficient transgenic Arabidopsis plants show multiple developmental alterations indicating opposite functions of cytokinins in the regulation of shoot and root meristem activity. Plant Cell 15:2532–2550
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sakamoto, T. Phytohormones and rice crop yield: strategies and opportunities for genetic improvement. Transgenic Res 15, 399–404 (2006). https://doi.org/10.1007/s11248-006-0024-1
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11248-006-0024-1