Late-maturity α-amylase expression in wheat is influenced by genotype, temperature and stage of grain development
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Late-maturity α-amylase (LMA) expression in wheat grains can be induced by either a cool temperature shock close to physiological maturity or continuous cool maximum temperatures during grain development.
Late-maturity α-amylase (LMA) is a genetic trait in wheat (Triticum aestivum L.) involving the production of α-amylase during grain development, which can result in an unacceptably low Falling Number (FN) in mature grain and consequent grain downgrading. Comparison of the FN test, an α-amylase activity assay and a high pI α-amylase-specific ELISA on the same meal samples gave equivalent results; ELISA was used for further experiments because of its isoform specificity. A cool temperature shock during the middle stages of grain development is known to induce LMA and is used for phenotypic screening. It was determined that a cool temperature treatment of seven days was required to reliably induce LMA. Glasshouse studies performed in summer and winter demonstrated that temperature affected the timing of sensitivity to cool-shock by altering the rate and duration of grain development, but that the sensitive grain developmental stage was unchanged at 35–45% moisture content. Wheat varieties with Rht-B1b or Rht-D1b dwarfing genes responded to a cool-shock only from mid grain filling until physiological maturity, whilst genotypes with Rht8c or without a dwarfing gene expressed LMA in response to a cool-shock during a wider developmental range. A continuous cool maximum temperature regimen (23 °C/15 °C day/night) during grain development also resulted in LMA expression and showed a stronger association with field expression than the cool-shock treatment. These results clarify how genotype, temperature and grain developmental stage determine LMA expression, and allow for the improvement of LMA phenotypic screening methods.
KeywordsDwarfing genes Falling number Grain filling High pI α-amylase Reduced height (Rht) Triticum aestivum
We would like to thank the Australian Grains Research and Development Corporation for funding support (Grant no. UA00150) and provision of the ELISA polyclonal and monoclonal antibodies under a research-only licensing agreement.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Armstrong R, Potgieter A, Mares D, Mrva K, Brider J, Hammer G (2019) An integrated framework for predicting the risk of experiencing temperature conditions that may trigger late maturity alpha-amylase in wheat across Australia. Crop Pasture Sci. https://doi.org/10.1071/CP19005 CrossRefGoogle Scholar
- Detje H (1992) Effects of varying nitrogen rates on pre-harvest sprouting and α-amylase activity in cereals. J Agron Crop Sci 169(1–2):38–45. https://doi.org/10.1111/j.1439-037X.1992.tb01183.x CrossRefGoogle Scholar
- Hagberg S (1960) A rapid method for determining alpha-amylase activity. Cereal Chem 37(2):218–222Google Scholar
- Kindred DR, Gooding MJ, Ellis RH (2005) Nitrogen fertilizer and seed rate effects on Hagberg failing number of hybrid wheats and their parents are associated with α-amylase activity, grain cavity size and dormancy. J Sci Food Agric 85(5):727–742. https://doi.org/10.1002/jsfa.2025 CrossRefGoogle Scholar
- Lunn GD, Kettlewell PS, Major BJ, Scott RK (2001a) Effects of pericarp alpha-amylase activity on wheat (Triticum aestivum) Hagberg falling number. Ann Appl Biol 138(2):207–214. https://doi.org/10.1111/j.1744-7348.2001.tb00104.x CrossRefGoogle Scholar
- Major BJ, Kettlewell PS, Lunn GD (1996) The effects of a period of high temperature during grain development on alpha-amylase activity in winter wheat (Triticum aestivum) in the absence of sprouting. In: Noda K, Mares DJ (eds) Seventh symposium on pre-harvest sprouting in cereals 1995. Center for Academic Societies Japan, Osaka, pp 441–447Google Scholar
- Mrva K, Mares DJ (1996a) Control of late maturity α-amylase synthesis compared to enzyme synthesis during germination. In: Noda K, Mares DJ (eds) Seventh international symposium on pre-harvest sprouting in cereals 1995. Center for Academic Societies Japan, Osaka, pp 419–426Google Scholar
- Mrva K, Mares D, Cheong J (2008) Genetic mechanisms involved in late maturity α-amylase in wheat. In: Proceedings of the 11th international wheat genetics symposium, 2008, pp 940–942Google Scholar
- 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(6741):256–261. https://doi.org/10.1038/22307 CrossRefPubMedGoogle Scholar
- Perten H (1964) Application of the falling number method for evaluating alpha-amylase activity. Cereal Chem 41(3):127–140Google Scholar
- Tottman DR (1987) The decimal code for the growth stages of cereals, with illustrations. Ann Appl Biol 110(2):441–454. https://doi.org/10.1111/j.1744-7348.1987.tb03275.x CrossRefGoogle Scholar
- Wheat Quality Australia (2017) Wheat Classification GuidelinesGoogle Scholar