Water and heat stresses during grain formation affect the physicochemical properties of waxy maize starch

Abstract

BACKGROUND Maize is frequently subjected to simultaneous water (drought or waterlogging) and heat (HS) stresses during grain formation in southern China. This work examined the effect of high temperature combined with drought (HD) or waterlogging (HW) during grain formation on the starch physicochemical properties of two waxy maize hybrids, namely Suyunnuo5 (SYN5) and Yunuo7 (YN7). RESULTS Heat stress enlarged the starch granule size, and water stresses aggravated this effect. Heat stress reduced the ratio of small molecular weight fractions for both hybrids, and HD aggravated this reduction only in SYN5. Relative crystallinity in SYN5 was increased by stresses but in YN7 it was unaffected by HD, reduced by HS, and increased by HW. Fourier‐transform infrared (FTIR) spectrometry results showed that the 1045/1022 cm−1 ratio in SYN5 was not influenced by HW but was increased by other stresses, and that in YN7 it was increased by all stresses, with the highest value induced by HW. Peak viscosity was decreased, whereas gelatinization temperatures and retrogradation percentage were increased by all of these stresses. These effects were exacerbated by combined heat and water stresses. The maximum decomposition rate was severely increased by HW. CONCLUSION Drought or waterlogging at grain formation stage aggravated the detrimental effects of HS on the starch physicochemical properties of waxy maize. © 2020 Society of Chemical Industry

Starch morphological, structural, pasting, and thermal properties of waxy maize under different heat stress durations at grain formation stage

“…This finding indicated that the high temperature stressed starch forms an increasingly ordered structure. Similar results were also reported in rice (Lin et al, 2020) and in our previous study (Wang et al, 2021). The high 1047/1022 cm −1 ratio may be because the starch presents a large granule size and long amylopectin chain length (Wang et al, 2021).…”

“…Similar results were also reported in rice (Lin et al, 2020) and in our previous study (Wang et al, 2021). The high 1047/1022 cm −1 ratio may be because the starch presents a large granule size and long amylopectin chain length (Wang et al, 2021). Meanwhile, a study on high‐amylose maize starch demonstrated that small starch granules exhibit a high 1047/1022 cm −1 ratio (Lin et al, 2016).…”

“…Similar results were also reported in rice (Lin et al, 2020) and in our previous study (Wang et al, 2021). The high 1047/1022 cm −1 ratio may be because the starch presents a large granule size and long amylopectin chain length (Wang et al, 2021). Meanwhile, a study on high-amylose maize starch demonstrated that small starch granules exhibit a high F I G U R E 4 Starch FTIR profiles of two waxy maize hybrids under ambient temperature, 5-and 10-day heat stress conditions (SYN5, Suyunuo5; YN7, Yunuo7; AT, ambient temperature; HS5, 5-day heat stress; HS10, 10-day heat stress.…”

“…Studies on rice (Fan et al, 2019;Yao et al, 2020), maize (Gu et al, 2018;Lu et al, 1996Lu et al, , 2014, barley (Cuesta-Seijo et al, 2019), and wheat (Thitisaksakul et al, 2012) also showed that gelatinization temperatures increase by HS. However, ΔH gel in response to HS is dependent on hybrids and stress stages (Gu et al, 2018;Lu et al, 2016;Wang et al, 2021). High gelatinization temperatures may be due to the high ratio of long amylopectin chains, high relative crystallinity, and increasingly ordered form of starch (Hsieh et al, 2019).…”

Application of Exogenous 6‐benzyladenine at the Silking‐Stage Improves the Starch Quality of Waxy Maize Suffering from Post‐Silking Drought Stress

“…[15,17] Zhang et al [27] reported that the F1/F2 ratio of wheat starch is reduced and increased by moderate and severe drought at the late growth stage. In our previous study, we observed that a 2-week drought increases the fraction of high-molecular weight amylopectin branch chains, [28] and the discrepancy observed herein might be due to different drought durations. In comparison with that in YN7, the F1/F2 ratio in JKN2000 was lower at all treatments, indicating JKN2000's high proportion of high-molecular weight amylopectin branch chains.…”