Diurnal Changes in Water Soluble Carbohydrate Components in Leaves and Sucrose Associated TaSUT1 Gene Expression during Grain Development in Wheat

Abstract

In plant tissues, sugar levels are determined by the balance between sugar import, export, and sugar synthesis. So far, water soluble carbohydrate (WSC) dynamics have not been investigated in a diurnal context in wheat stems as compared to the dynamics in flag leaves during the terminal phases of grain filling. Here, we filled this research gap and tested the hypothesis that WSC dynamics interlink with gene expression of TaSUT1. The main stems and flag leaves of two genotypes, Westonia and Kauz, were sampled at four hourly intervals over a 24 h period at six developmental stages from heading to 28 DAA (days after anthesis). The total levels of WSC and WSC components were measured, and TaSUT1 gene expression was quantified at 21 DAA. On average, the total WSC and fructan levels in the stems were double those in the flag leaves. In both cultivars, diurnal patterns in the total WSC and sucrose were detected in leaves across all developmental stages, but not for the fructans 6-kestose and bifurcose. However, in stems, diurnal patterns of the total WSC and fructan were only found at anthesis in Kauz. The different levels of WSC and WSC components between Westonia and Kauz are likely associated with leaf chlorophyll levels and fructan degradation, especially 6-kestose degradation. High correlation between levels of TaSUT1 expression and sucrose in leaves indicated that TaSUT1 expression is likely to be influenced by the level of sucrose in leaves, and the combination of high levels of TaSUT1 expression and sucrose in Kauz may contribute to its high grain yield under well-watered conditions.

The Role of Sugars in Plant Responses to Stress and Their Regulatory Function during Development

“…The accumulation, metabolism, and transport of sugars, and especially those of sucrose, are strongly dependent on both environmental and physical parameters such as temperature, CO 2 , photoperiod, and the circadian rhythm as well as interactions with plant hormones. Four articles discussed the implication of cold, photoperiod, and hormonal control in soluble sugar and sucrose contents in relation to plant development phases [26][27][28][29].…”

“…Thus, addressing the diurnal patterns of sugar transport in wheat during the period of grain filling is of major concern. Al-Sheikh Ahmed et al [29] investigated the possible diurnal changes in water-soluble carbohydrates that occur in correlation with different expression levels of the sucrose transporter TaSUT1 gene in two different wheat varieties, Kauz and Westonia. It was suggested that a higher expression of TaSUT1 in leaves that correlates well with the high sucrose levels observed in the variety Kauz can contribute to a grain weight increase in this variety.…”

Optimization of Extraction Parameters and Characterization of Tunisian Date Extract: A Scientific Approach Toward Their Utilization

“…Additionally, the migration of the active component to the food simulant is affected by the polarity of the migrant and simulating media. Also, the sum of glucose, fructose, sucrose, and fructans is termed “water soluble carbohydrate” (Al-Sheikh Ahmed et al 2020 ). Phillips et al ( 2009 ) confirmed this result by comparing the antioxidant activity content among natural sweeteners (fruit sugars, e.g., date sugar) versus refined sugar and found that date sugar has the highest antioxidant activity of the natural sweeteners studied.…”