The effects of drought treatments on biosynthesis and structure of maize starches with different amylose content
Wenhao Wu1, Jianzhou Qu1, Andreas Blennow2
1Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Maize Engineering Technology Research Centre of Shaanxi Province, Yangling 712100, Shaanxi, China.
Abstract:
We investigated the effects of drought stress (DS) on maize varieties with different amylose content (AC). In starches with AC of 33 %, DS increased the contents of amylopectin (AP) chains with a degree of polymerization (DP) > 36 and decreased the AP chains with DP ≤ 36, while the AC was unchanged. DS decreased the crystallinity, the thickness of both amorphous and crystalline lamellae, and average granular size. In contrast, the digestibility increased. For starches with AC of 45 %, DS increased the content of AP chains with DP > 24 and AC, while the contents of AP chains with DP ≤ 24 decreased. DS produced starch with thinner crystalline lamellae, thicker amorphous lamellae, more elongated and larger granules. The digestibility of the starches decreased. In starches with AC of 53 %, moderate DS led to similar structural and functional changes as found for starches with AC of 45 %. Finally, severe DS resulted in the decrease of AC.
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