The Potential Function of SiLOX4 on Millet Discoloration during Storage in Foxtail Millet
The Potential Function of SiLOX4 on Millet Discoloration during Storage in Foxtail Millet
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DOI：
10.3390/agriculture12081283
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
Qi Ma;Junjie Wang;Lu Cheng;Yaqiong Li;Qianxiang Zhang;Hongying Li;Yuanhuai Han;Xiaoxing Zhen;Bin Zhang
中科院分区：
文献类型：
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作者：
Qi Ma;Junjie Wang;Lu Cheng;Yaqiong Li;Qianxiang Zhang;Hongying Li;Yuanhuai Han;Xiaoxing Zhen;Bin Zhang
谷色是消费者评价谷子品质的重要指标。小米的黄色主要是因为积累了类胡萝卜素，这是人体营养所必需的。然而，小米在储存过程中由于类胡萝卜素降解而变色，严重降低了小米产品的营养和商业价值。以9806-1和宝米浑子两个谷子品种为试材，分析了谷子贮藏变色的主要品质性状。结果表明，谷子在贮藏过程中变色是由类胡萝卜素降解引起的，不同基因型的变色率不同。9806-1的类胡萝卜素还原率（32.2%）高于宝蜜浑子（10.5%）。类胡萝卜素的减少与SiLOX蛋白的表达呈正相关，表明谷子中SiLOX蛋白在贮藏过程中类胡萝卜素的减少中起主要作用。分析了这两个品种在不同籽粒成熟阶段（S1 ~ S3）SiLOX基因家族的表达谱，以确定响应谷子变色的关键SiLOX基因。SiLOX 2、SiLOX 3和SiLOX 4的连续低表达导致了保蜜浑子中SiLOX蛋白的低水平。此外，SiLOX 4基因在小米混籽成熟后期的表达量较低，与小米变色程度低相关，表明SiLOX 4基因可能是调控小米变色的关键基因。本研究为谷子贮藏过程中类胡萝卜素降解机理的研究提供了重要信息，为进一步了解谷子类胡萝卜素代谢规律奠定了基础。
Millet color is an important index for consumers to assess foxtail millet quality. The yellow color of millet is mainly because of the accumulation of carotenoids, which are essential for human nutrition. However, the discoloration of millet during storage due to carotenoid degradation seriously reduces the nutritional and commercial value of millet products. The essential quality traits of millet discoloration during storage were analyzed using two foxtail millet varieties, namely 9806-1 and Baomihunzi. We observed that the millet discoloration was caused by carotenoid degradation during storage, and different genotypes exhibited different discoloration rates. The carotenoid reduction rate in 9806-1 (32.2%) was higher than that in Baomihunzi (10.5%). The positive correlation between carotenoid reduction and the expression of SiLOX protein indicated that SiLOX from foxtail millet played a major role in carotenoid reduction during storage. The expression profiles of the SiLOX gene family were analyzed at different grain maturing stages, from S1 to S3, in these two varieties to determine the key SiLOX genes responsive to millet discoloration in foxtail millet. The consecutively low expression of SiLOX2, SiLOX3, and SiLOX4 contributed to the low level of SiLOX protein in Baomihunzi. Furthermore, the undetectable expression of SiLOX4 in the later stage of maturation in Baomihunzi was associated with low discoloration, indicating that SiLOX4 might be a key gene in regulating the discoloration of millet. This study provided critical information on the mechanism of carotenoid degradation during millet storage and laid the foundation for further understanding of carotenoid metabolism in foxtail millet.