Abstract
Key message
Knocking down GW2 enhances grain size by regulating genes encoding the synthesis of cytokinin, gibberellin, starch and cell wall.
Abstract
Raising crop yield is a priority task in the light of the continuing growth of the world's population and the inexorable loss of arable land to urbanization. Here, the RNAi approach was taken to reduce the abundance of Grain Weight 2 (GW2) transcript in the durum wheat cultivar Svevo. The effect of the knockdown was to increase the grains' starch content by 10–40%, their width by 4–13% and their surface area by 3–5%. Transcriptomic profiling, based on a quantitative real-time PCR platform, revealed that the transcript abundance of genes encoding both cytokinin dehydrogenase 1 and the large subunit of ADP-glucose pyrophosphorylase was markedly increased in the transgenic lines, whereas that of the genes encoding cytokinin dehydrogenase 2 and gibberellin 3-oxidase was reduced. A proteomic analysis of the non-storage fraction extracted from mature grains detected that eleven proteins were differentially represented in the transgenic compared to wild-type grain: some of these were involved, or at least potentially involved, in cell wall development, suggesting a role of GW2 in the regulation of cell division in the wheat grain.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Explore related subjects
Discover the latest articles and news from researchers in related subjects, suggested using machine learning.References
Bednarek J, Boulaflous A, Girousse C, Ravel C, Tassy C, Barret P, Bouzidi MF, Mouzeyar S (2012) Down-regulation of the TaGW2 gene by RNA interference results in decreased grain size and weight in wheat. J Exp Bot 63:5945–5955. https://doi.org/10.1093/jxb/ers249
Camerlengo F, Sestili F, Silvestri M, Colaprico G, Margiotta B, Ruggeri R, Lupi R, Masci S, Lafiandra D (2017) Production and molecular characterization of bread wheat lines with reduced amount of α-type gliadins. BMC Plant Biol 17:248. https://doi.org/10.1186/s12870-017-1211-3
Christensen AH, Quail PF (1996) Ubiquitin promoter-based vectors for high level expression of selectable and/or screenable marker genes in monocotyledonous plants. Trans Res 5:213–218
Cunsolo V, Foti S, Saletti R (2004) Mass spectrometry in the characterisation of cereal seed proteins. Eur J Mass Spectrom 10:359–370. https://doi.org/10.1255/ejms.609
Cunsolo V, Muccilli V, Saletti R, Foti S (2012) Mass spectrometry in the proteome analysis of mature cereal kernels. Mass Spectrom Rev 31:448–465. 10.1002/mas.20347
Dornez E, Croes E, Gebruers K, De Coninck B, Cammue BP, Delcour JA, Courtin CM (2010) Accumulated evidence substantiates a role for three classes of wheat xylanase inhibitors in plant defense. Critic Rev Plant Sci 29:244–264. https://doi.org/10.1080/07352689.2010.487780
Du D, Gao X, Geng J, Li Q, Li L, Lv Q, Li X (2016) Identification of key proteins and networks related to grain development in wheat (Triticum aestivum L.) by comparative transcription and proteomic analysis of allelic variants in TaGW2-6A. Front Plant Sci 7:922. https://doi.org/10.3389/fpls.2016.00922
Elliott G, Durand A, Hughes RK, D'Ovidio R, Juge N (2009) Isolation and characterisation of a xylanase inhibitor Xip-II gene from durum wheat. J Cereal Sci 50:324–331. https://doi.org/10.1016/j.jcs.2009.06.013
Felsenstein J (1985) Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39:783–791
Gebruers K, Courtin CM, Goesaert H, Campenhout SV, Delcour JA (2002) Endoxylanase inhibition activity in different European wheat cultivars and milling fractions. Cereal Chem 79:613–616. https://doi.org/10.1094/CCHEM.2002.79.5.613
Geng J, Li L, Lv Q, Zhao Y, Liu Y, Zhang L, Li X (2017) TaGW2-6A allelic variation contributes to grain size possibly by regulating the expression of cytokinins and starch-related genes in wheat. Planta 246:1153–1163. https://doi.org/10.1007/s00425-017-2759-8
Glass M, Barkwill S, Unda F, Mansfield SD (2015) Endo-β-1, 4-glucanases impact plant cell wall development by influencing cellulose crystallization. J Integr Plant Biol 57:396–410. https://doi.org/10.1111/jipb.12353
Hong Y, Chen L, Du L-p SuZ, Wang J, Ye X, Qi L, Zhang Z (2014) Transcript suppression of TaGW2 increased grain width and weight in bread wheat. Funct Integr Gen 14:341–349. https://doi.org/10.1007/s10142-014-0380-5
Huttly AK, Phillips AL (1995) Gibberellin-regulated plant genes. Physiol Plant 95:310–317
Jaiswal V, Gahlaut V, Mathur S, Agarwal P, Khandelwal MK, Khurana JP, Tyagi AK, Balyan HS, Gupta PK (2015) Identification of novel SNP in promoter sequence of TaGW2-6A associated with grain weight and other agronomic traits in wheat (Triticum aestivum L.). PLoS ONE 10:e0129400. https://doi.org/10.1371/journal.pone.0129400
Jeon JS, Ryoo N, Hahn TR, Walia H, Nakamura Y (2010) Starch biosynthesis in cereal endosperm. Plant Physiol Biochem 48:383–392. https://doi.org/10.1016/j.plaphy.2010.03.006
Kadkol G, Sissons M (2016) Durum wheat: overview. In: Wrigley C, Corke H, Seetharaman K, Faubion J (eds) Encyclopedia of food grains, 2nd edn. Academic Press Inc., San Diego, pp 117–124
Li Q, Li L, Yang X, Warburton M, Bai G, Dai J, Li J, Yan J (2010) Relationship, evolutionary fate and function of two maize co-orthologs of rice GW2 associated with kernel size and weight. BMC Plant Biol 10:143. https://doi.org/10.1186/1471-2229-10-143
Li Q, Li L, Liu Y, Lv Q, Zhang H, Zhu J, Li X (2017) Influence of TaGW2-6A on seed development in wheat by negatively regulating gibberellin synthesis. Plant Sci 263:226–235. https://doi.org/10.1016/j.plantsci.2017.07.019
Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT method. Methods 25:402–408
Locascio A, Roig-Villanova I, Bernardi J, Varotto S (2014) Current perspectives on the hormonal control of seed development in Arabidopsis and maize: a focus on auxin. Front Plant Sci 5:412. https://doi.org/10.3389/fpls.2014.00412
Lopez-Casado G, Urbanowicz BR, Damasceno CMB, Rose JKC (2008) Plant glycosyl hydrolases and biofuels: a natural marriage. Curr Opin Plant Biol 11:329–333. https://doi.org/10.1016/j.pbi.2008.02.010
Nieuwland J, Feron R, Huisman BA, Fasolino A, Hilbers CW, Derksen J, Mariani C (2005) Lipid transfer proteins enhance cell wall extension in tobacco. Plant Cell 17:2009–2019. https://doi.org/10.1105/tpc.105.032094
Qin L, Zhao J, Li T, Hou J, Zhang X, Hao C (2017) TaGW2, a good reflection of wheat polyploidization and evolution. Front Plant Sci 8:318. https://doi.org/10.3389/fpls.2017.00318
Sestili F, Janni M, Doherty A, Botticella E, D'Ovidio R, Masci S, Jones H, Lafiandra D (2010) Increasing the amylose content of durum wheat through silencing of the SBEIIa genes. BMC Plant Biol 10:144. https://doi.org/10.1186/1471-2229-10-144
Sestili F, Palombieri S, Botticella E, Mantovani P, Bovina R, Lafiandra D (2015) TILLING mutants of durum wheat result in a high amylose phenotype and provide information on alternative splicing mechanisms. Plant Sci 233:127–133. https://doi.org/10.1016/j.plantsci.2015.01.009
Simmonds J, Scott P, Brinton J, Mestre TC, Bush M, Del Blanco A, Dubcovsky J, Uauy C (2016) A splice acceptor site mutation in TaGW2-A1 increases thousand grain weight in tetraploid and hexaploid wheat through wider and longer grains. Theor Appl Genet 129:1099–1112. https://doi.org/10.1007/s00122-016-2686-2
Song X-J, Huang W, Shi M, Zhu M-Z, Lin H-X (2007) A QTL for rice grain width and weight encodes a previously unknown RING-type E3 ubiquitin ligase. Nat Genet 39:623–630. https://doi.org/10.1038/ng2014
Sreenivasulu N, Schnurbusch T (2012) A genetic playground for enhancing grain number in cereals. Trends Plant Sci 17:91–101. https://doi.org/10.1016/j.tplants.2011.11.003
Su Z, Hao C, Wang L, Dong Y, Zhang X (2011) Identification and development of a functional marker of TaGW2 associated with grain weight in bread wheat (Triticum aestivum L.). Theor Appl Genet 122:211–223. https://doi.org/10.1007/s00122-010-1437-z
Tanabata T, Shibaya T, Hori K, Ebana K, Yano M (2012) SmartGrain: high-throughput phenotyping software for measuring seed shape through image analysis. Plant Physiol 160:1871–1880. https://doi.org/10.1104/pp.112.205120
Tosi P, D'Ovidio R, Napier JA, Bekes F, Shewry PR (2004) Expression of epitope-tagged LMW glutenin subunits in the starchy endosperm of transgenic wheat and their incorporation into glutenin polymers. Theor Appl Genet 108:468–476. https://doi.org/10.1007/s00122-003-1459-x
Wang NJ, Lee CC, Cheng CS, Lo WC, Yang YF, Chen MN, Lyu PC (2012) Construction and analysis of a plant non-specific lipid transfer protein database (nsLTPDB). BMC Genom 13:S9. https://doi.org/10.1186/1471-2164-13-S1-S9
Xing Y, Zhang Q (2010) Genetic and molecular bases of rice yield. Annu Rev Plant Biol 61:421–442. https://doi.org/10.1146/annurev-arplant-042809-112209
Yang Z, Bai Z, Li X, Wang P, Wu Q, Yang L, Li L, Li X (2012) SNP identification and allelic-specific PCR markers development for TaGW2, a gene linked to wheat kernel weight. Theor Appl Genet 125:1057–1068. https://doi.org/10.1007/s00122-012-1895-6
Zhai H, Feng Z, Du X, Song Y, Liu X, Qi Z, Song L, Li J, Li L, Peng H, Hu Z, Yao Y, Xin M, Xiao S, Sun Q, Ni Z (2018) A novel allele of TaGW2-A1 is located in a finely mapped QTL that increases grain weight but decreases grain number in wheat (Triticum aestivum L.). Theor Appl Genet 131:539–553. https://doi.org/10.1007/s00122-017-3017-y
Zhang X, Chen J, Shi C, Chen J, Zheng F, Tian J (2013) Function of TaGW2-6A and its effect on grain weight in wheat (Triticum aestivum L.). Euphytica 192:347–357. https://doi.org/10.1007/s10681-012-0858-y
Zhang Y, Li D, Zhang D, Zhao X, Cao X, Dong L, Liu J, Chen K, Zhang H, Gao C, Wang D (2018) Analysis of the functions of TaGW2 homeologs in wheat grain weight and protein content traits. Plant J 94:857–866. https://doi.org/10.1111/tpj.13903
Zürcher E, Müller B (2016) Cytokinin synthesis, signaling, and function-advances and new insights. Int Rev Cell Mol Biol 324:1–38. https://doi.org/10.1016/bs.ircmb.2016.01.001
Acknowledgements
The research was financially supported by Italian Ministry of Education, University and Research (MIUR): project PRIN 2010Z77XAX_001 “Identification and characterization of yield- and sustainability-related genes in durum wheat” and in the frame of the MIUR initiative “Departments of excellence”, Law 232/2016. The Bionanotech Research and Innovation Tower (BRIT, University of Catania) is gratefully acknowledged for making available the Orbitrap Fusion mass spectrometer.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Communicated by Rajeev K. Varshney.
This paper is dedicated to the memory of our colleague and friend Prof. Renato D'Ovidio.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Sestili, F., Pagliarello, R., Zega, A. et al. Enhancing grain size in durum wheat using RNAi to knockdown GW2 genes. Theor Appl Genet 132, 419–429 (2019). https://doi.org/10.1007/s00122-018-3229-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00122-018-3229-9