Effects of post‐silking drought stress degree on grain yield and quality of waxy maize

Abstract

BACKGROUND Drought stress (DS) induced by post‐silking have a major impact on the yield and quality of maize. In this study, the effects of different degrees of DS after pollination on grain filling, starch and protein metabolism, and functional properties were investigated using two waxy maize cultivars as materials. The levels of DS that were investigated were ‘mild water stress’ (WS1), ‘moderate water stressed’ (WS2), and ‘severe waterstressed’ (WS3). RESULTS Drought stress decreased grain fresh weight, dry weight, and moisture content in both cultivars during grain filling, and reduced kernel number, kernel weight, and grain yield at maturity. The effect on grain development and yield formation gradually increased with drought aggravation. The water stress (WS) treatment downregulated the enzymatic activities related to starch biosynthesis during grain‐filling process, accompanied by a decrease in soluble sugar and starch deposition. The WS treatment increased the enzymatic activities involved in protein synthesis during grain‐filling process, thereby increasing the protein content of grains. On average, WS2 and WS3 treatments reduced the pasting viscosities and increased the gelatinization temperatures of grains, with WS3 having the greatest effect. However, the changes of setback viscosity, gelatinization enthalpy, retrogradation enthalpy, and retrogradation percentage under WS treatment were inconsistent in both cultivars. Pearson correlation analysis showed that starch content was negatively correlated with gelatinization temperatures and positively correlated with pasting viscosities in both cultivars. However, grain pasting and gelatinization properties have opposite correlations with protein content and starch content. CONCLUSIONS These findings suggest that post‐silking DS regulated the grain‐filling process and starch and protein biosynthesis, which influenced grain yield and quality. © 2022 Society of Chemical Industry.

Effects of water deficit at different stages on growth and ear quality of waxy maize

“…Debon et al (1998) and Silva et al (2001) found that the increase in the starch concentration of fresh fruit of potato was mainly due to the concentration effect caused by the decrease in water content in fresh fruit. Guo et al (2022) and Shi et al (2018) also showed an increase in starch content in fresh waxy maize grains under drought stress and indicated that acceleration of grain filling and decreases in grain water content under drought (Figure 7F) might be the main reasons for the starch content increase. Meanwhile, water deficit caused a significantly increase in abscisic acid (ABA) content in maize plant tissues, and then led to the activity increases of four key enzymes related closely to converting soluble sugar into starch (Zhang et al, 2012).…”

“…The reduction of photosynthetic rate under water deficit may lead to a reduction of plant photoassimilate deposition and ultimately the loss of grain yield ( Kimaro et al., 2015 ; Ye et al., 2020a ; Ulfat et al., 2021 ). Previous studies have shown that a water deficit during grain filling reduced the grain fresh weight, water content, and grains per ear of waxy maize ( Guo et al., 2022 ). In this study, fresh ear yield with husk and fresh ear yield were significantly reduced, and the grain number per ear and 100-grain weight also showed some reducing trends under the D V6–VT and D VT–R2 treatments.…”

“…(2001) found that the increase in the starch concentration of fresh fruit of potato was mainly due to the concentration effect caused by the decrease in water content in fresh fruit. Guo et al. (2022) and Shi et al.…”

Key Stage and Its Optimum Meteorological Conditions Affecting the Nutritional Quality of Maize

“…The difference in meteorological factors caused by the sowing date is the main reason for the change in maize grain quality. The grain-filling period is the key stage for maize grain quality, especially for endosperm cells and starch granule formation [22], which is sensitive to environmental adversity [23]. According to the VIP value between meteorological conditions and the main nutritional quality during the whole growing period, it was found that although environmental factors are the key factors affecting grain quality trait, there are differences in the starting point of the key stage and the duration of the key stage (Figure 3).…”

Transcriptome sequencing and metabolome analysis reveal the molecular mechanism of Salvia miltiorrhiza in response to drought stress

“…Moreover, due to their high reactivity, excess ROS are hazardous and can destroy nucleic acids, proteins, and lipids [ 5 ]. In addition, severe drought stress could reduce yield and quality, which in turn affect real productivity [ 6 ].…”