# Effects of Climate Conditions before Harvest Date on Edamame Metabolome
## 1 Introduction  
Edamame, the immature seed of the soybean (_Glycine max_ L. _Merr._), is mainly eaten in Japan and other East Asian countries. Soybeans, which are fully ripened seeds, are cultivated as one of the major crops around the world. Because the seeds are rich in protein and lipids, they have a wide range of uses, including food, edible oil, and livestock feed. Similar to soybeans, edamame is rich in protein, sugar, fat, vitamin C, and vitamin B1; thus, it is a popular food, as it has high nutritional value and taste [1]. Many studies have been conducted on the conditions for harvesting high-quality edamame efficiently by analyzing information such as the variety, planting date, harvest date, edamame color, and pod weight using artificial neural network analysis [2] by using digital imaging technology and computer vision algorithms to characterize the major traits of edamame's shoot architecture [3], or by applying a spectroscopy-based machine learning technique [4]. In recent years, ethyl methanesulfonate-based breeding improvements and genome-wide-association study-based searches for useful genes have been performed, and these obtained unique mutants flowered considerably earlier than the wild type and identified single nucleotide polymorphisms (SNPs) related to the amounts of sucrose and Ala, respectively [5, 6]. Previous studies reported the health functionality of edamame, especially its effects on obesity and diabetes [7, 8]. In addition, practical research has being conducted, such as a previouscomprehensive analysis of the changes in edamame composition due to storage conditions using actual distribution conditions [9]. Differences in the microclimate, caused by geographical conditions or artificial agricultural techniques, affect the quality of agricultural products. In grape-producing regions, such as those in Europe, there are differences in the grape quality from field to field, and this difference is thought to be due to various environmental factors, including the microclimate called terroric [10]. Previous studies reported that the temperature of the field environment affects the coloration of grapes and that excessive sunlight has a negative effect on the amount of flavonoids and flavor-related components [11; 12]. Metabolome analysis has also revealed that sunlight causes changes in the amounts of other metabolites in grapes [13; 14]. It has also been reported that climate conditions affect the volatile amount of grapes and are related to the quality of wine [15; 16]. In addition, there are many reports of a relationship between the quality of agricultural products and meteorological conditions, such as sunshine duration, rainfall, and temperature, during cultivation, including research on abiotic stress responses. For example, in tomatoes, the level of antioxidant metabolites, such as ascorbic acid and lycopene, fluctuate because of temperature and sunlight [17], and the amount of sugars and carotenoids was changed using artificial fog [18]. In rice, starch accumulation was inhibited, and amino acid accumulation was induced in grains during ripening by high temperatures [19; 20]. Climate conditions have been reported to affect the quality of agricultural products such as asparagus [21], common beans [22], cherries [23], and pomegranates [24]. However, most of these studies used agricultural products that had been exposed to the same climate conditions throughout the study period and used agricultural materials such as shade or mulch. Few studies have investigated the relationship between the differences in climate conditions for several days before harvesting and the quality of agricultural products. In this study, the same variety of edamame was harvested under different climate conditions. A previous study reported that the cumulative amount of climate over two or more days is important for physiological phenomena such as flowering and the germination of plants. We hypothesized that the climate conditions just before harvest would affect the quality of edamame soybeans.