Brassinosteroids Regulate Grain Filling in Rice

Overview

Journal Plant Cell

Publisher Oxford University Press

Specialties Biology
Cell Biology

Date 2008 Aug 19

PMID 18708477

Citations 147

Authors

Chuan-Yin Wu

Anthony Trieu

Parthiban Radhakrishnan

Shing F Kwok

Sam Harris

Ke Zhang

Jiulin Wang

Jianmin Wan

Huqu Zhai

Suguru Takatsuto

Shogo Matsumoto

Shozo Fujioka

Kenneth A Feldmann

Roger I Pennell

Affiliations

Soon will be listed here.

Abstract

Genes controlling hormone levels have been used to increase grain yields in wheat (Triticum aestivum) and rice (Oryza sativa). We created transgenic rice plants expressing maize (Zea mays), rice, or Arabidopsis thaliana genes encoding sterol C-22 hydroxylases that control brassinosteroid (BR) hormone levels using a promoter that is active in only the stems, leaves, and roots. The transgenic plants produced more tillers and more seed than wild-type plants. The seed were heavier as well, especially the seed at the bases of the spikes that fill the least. These phenotypic changes brought about 15 to 44% increases in grain yield per plant relative to wild-type plants in greenhouse and field trials. Expression of the Arabidopsis C-22 hydroxylase in the embryos or endosperms themselves had no apparent effect on seed weight. These results suggested that BRs stimulate the flow of assimilate from the source to the sink. Microarray and photosynthesis analysis of transgenic plants revealed evidence of enhanced CO(2) assimilation, enlarged glucose pools in the flag leaves, and increased assimilation of glucose to starch in the seed. These results further suggested that BRs stimulate the flow of assimilate. Plants have not been bred directly for seed filling traits, suggesting that genes that control seed filling could be used to further increase grain yield in crop plants.

Citing Articles

Rice grain size: current regulatory mechanisms and future perspectives.

Yaseen M, Tariq N, Kanwal R, Farooq A, Wang H, Yuan H J Plant Res. 2025; .

PMID: 40056359 DOI: 10.1007/s10265-025-01626-8.

Epibrassinolide Regulates Expression Though the Transcription Factor of MYBR17 in Maize.

Li H, He X, Lv H, Zhang H, Peng F, Song J Biomolecules. 2025; 15(1).

PMID: 39858488 PMC: 11763093. DOI: 10.3390/biom15010094.

Exogenous 2,4-Epibrassinolide Alleviates Alkaline Stress in Cucumber by Modulating Photosynthetic Performance.

Nie W, He Q, Ma J, Guo H, Shi Q Plants (Basel). 2025; 14(1.

PMID: 39795313 PMC: 11723107. DOI: 10.3390/plants14010054.

Hormonal regulation and crosstalk during early endosperm and seed coat development.

Pankaj R, Lima R, Figueiredo D Plant Reprod. 2024; 38(1):5.

PMID: 39724433 PMC: 11671439. DOI: 10.1007/s00497-024-00516-8.

Physiological Mechanism of EBR for Grain-Filling and Yield Formation of Tartary Buckwheat.

Liu H, Wang Q, Cheng T, Wan Y, Wei W, Ye X Plants (Basel). 2024; 13(23).

PMID: 39683127 PMC: 11644248. DOI: 10.3390/plants13233336.

References

Ryoo N, Yu C, Park C, Baik M, Park I, Cho M . Knockout of a starch synthase gene OsSSIIIa/Flo5 causes white-core floury endosperm in rice (Oryza sativa L.). Plant Cell Rep. 2007; 26(7):1083-95. DOI: 10.1007/s00299-007-0309-8. View

Tanabe S, Ashikari M, Fujioka S, Takatsuto S, Yoshida S, Yano M . A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant, dwarf11, with reduced seed length. Plant Cell. 2005; 17(3):776-90. PMC: 1069698. DOI: 10.1105/tpc.104.024950. View

Choe S, Dilkes B, Fujioka S, Takatsuto S, Sakurai A, Feldmann K . The DWF4 gene of Arabidopsis encodes a cytochrome P450 that mediates multiple 22alpha-hydroxylation steps in brassinosteroid biosynthesis. Plant Cell. 1998; 10(2):231-43. PMC: 143988. DOI: 10.1105/tpc.10.2.231. View

Fritzius T, AESCHBACHER R, Wiemken A, Wingler A . Induction of ApL3 expression by trehalose complements the starch-deficient Arabidopsis mutant adg2-1 lacking ApL1, the large subunit of ADP-glucose pyrophosphorylase. Plant Physiol. 2001; 126(2):883-9. PMC: 111177. DOI: 10.1104/pp.126.2.883. View

Hong Z, Ueguchi-Tanaka M, Fujioka S, Takatsuto S, Yoshida S, Hasegawa Y . The Rice brassinosteroid-deficient dwarf2 mutant, defective in the rice homolog of Arabidopsis DIMINUTO/DWARF1, is rescued by the endogenously accumulated alternative bioactive brassinosteroid, dolichosterone. Plant Cell. 2005; 17(8):2243-54. PMC: 1182486. DOI: 10.1105/tpc.105.030973. View

Satoh H, Nishi A, Yamashita K, Takemoto Y, Tanaka Y, Hosaka Y . Starch-branching enzyme I-deficient mutation specifically affects the structure and properties of starch in rice endosperm. Plant Physiol. 2003; 133(3):1111-21. PMC: 281607. DOI: 10.1104/pp.103.021527. View

Bainbridge K, Guyomarch S, Bayer E, Swarup R, Bennett M, Mandel T . Auxin influx carriers stabilize phyllotactic patterning. Genes Dev. 2008; 22(6):810-23. PMC: 2275433. DOI: 10.1101/gad.462608. View

Xu D, Lei M, Wu R . Expression of the rice Osgrp1 promoter-Gus reporter gene is specifically associated with cell elongation/expansion and differentiation. Plant Mol Biol. 1995; 28(3):455-71. DOI: 10.1007/BF00020394. View

Wang , Jiang , Oard . Structure, expression and promoter activity of two polyubiquitin genes from rice (Oryza sativa L.). Plant Sci. 2000; 156(2):201-211. DOI: 10.1016/s0168-9452(00)00255-7. View

10.

Johansson H, Sterky F, Amini B, Lundeberg J, Kleczkowski L . Molecular cloning and characterization of a cDNA encoding poplar UDP-glucose dehydrogenase, a key gene of hemicellulose/pectin formation. Biochim Biophys Acta. 2002; 1576(1-2):53-8. DOI: 10.1016/s0167-4781(02)00292-0. View

11.

Schruff M, Spielman M, Tiwari S, Adams S, Fenby N, Scott R . The AUXIN RESPONSE FACTOR 2 gene of Arabidopsis links auxin signalling, cell division, and the size of seeds and other organs. Development. 2005; 133(2):251-61. DOI: 10.1242/dev.02194. View

12.

Misson J, Raghothama K, Jain A, Jouhet J, Block M, Bligny R . A genome-wide transcriptional analysis using Arabidopsis thaliana Affymetrix gene chips determined plant responses to phosphate deprivation. Proc Natl Acad Sci U S A. 2005; 102(33):11934-9. PMC: 1188001. DOI: 10.1073/pnas.0505266102. View

13.

Fujioka S, Takatsuto S, Yoshida S . An early C-22 oxidation branch in the brassinosteroid biosynthetic pathway. Plant Physiol. 2002; 130(2):930-9. PMC: 166619. DOI: 10.1104/pp.008722. View

14.

Nemhauser J, Mockler T, Chory J . Interdependency of brassinosteroid and auxin signaling in Arabidopsis. PLoS Biol. 2004; 2(9):E258. PMC: 509407. DOI: 10.1371/journal.pbio.0020258. View

15.

Yu J, Huang L, Hu W, Zhou Y, Mao W, Ye S . A role for brassinosteroids in the regulation of photosynthesis in Cucumis sativus. J Exp Bot. 2004; 55(399):1135-43. DOI: 10.1093/jxb/erh124. View

16.

Li X, Qian Q, Fu Z, Wang Y, Xiong G, Zeng D . Control of tillering in rice. Nature. 2003; 422(6932):618-21. DOI: 10.1038/nature01518. View

17.

Sasaki A, ASHIKARI M, Itoh H, Nishimura A, Swapan D, Ishiyama K . Green revolution: a mutant gibberellin-synthesis gene in rice. Nature. 2002; 416(6882):701-2. DOI: 10.1038/416701a. View

18.

Wang R, Okamoto M, Xing X, Crawford N . Microarray analysis of the nitrate response in Arabidopsis roots and shoots reveals over 1,000 rapidly responding genes and new linkages to glucose, trehalose-6-phosphate, iron, and sulfate metabolism. Plant Physiol. 2003; 132(2):556-67. PMC: 166997. DOI: 10.1104/pp.103.021253. View

19.

Szekeres M, Nemeth K, Mathur J, Kauschmann A, Altmann T, Redei G . Brassinosteroids rescue the deficiency of CYP90, a cytochrome P450, controlling cell elongation and de-etiolation in Arabidopsis. Cell. 1996; 85(2):171-82. DOI: 10.1016/s0092-8674(00)81094-6. View

20.

Reinhardt B, Hanggi E, Muller S, Bauch M, Wyrzykowska J, Kerstetter R . Restoration of DWF4 expression to the leaf margin of a dwf4 mutant is sufficient to restore leaf shape but not size: the role of the margin in leaf development. Plant J. 2007; 52(6):1094-104. DOI: 10.1111/j.1365-313X.2007.03304.x. View