Key Message

Carbon competition between starch and oil biosynthesis during seed development of Styrax tonkinensis has been reported, but reserve dynamics indicate an absence of significant carbon competition in other Styrax species.

Abstract

The accumulation of different storage reserves during seed development can be competitive. Carbon competition (i.e., carbon flow into starch instead of oil) has been reported in Styrax tonkinensis (Pierre) Craib ex Hartwich. In this study, developmental patterns in morphology and the accumulation of major biochemical fractions of five other Styrax species (S. calvescens Perkins, S. dasyantha Perk., S. faberi Perk., S. japonicus Sieb. et Zucc., and S. odoratissimus Champ. ex Benth.) were analyzed over 50 days. In all species, kernel fresh matter and dry matter increased during development, while the percent water content trended downwards to lower than 40% at the last sampling date. The time to maturity varied with species, as did the evolution of oil, fatty acids composition, sugar, starch, and protein. Contents of these major reserve fractions per kernel increased with development and were strongly correlated with each other. Final oil concentration ranged from 489 to 548 mg g⁻¹, and the proportions of major fatty acids (palmitic, oleic and linoleic acid) were similar across species (11–15%, 39–41% and 43–47%, respectively). In contrast, starch concentrations never exceeded 7–45 mg g⁻¹, depending on species and developmental stage. Final protein concentration ranged from 165 to 237 mg g⁻¹. A slowdown in the speed of oil accumulation midway during development may occur in S. faberi but was not present in the other species. None of the five Styrax species examined here presented evidence for significant carbon competition between starch and oil accumulation.

中文翻译：

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五个具有生物燃料生产潜力的菊科植物种子储备积累的比较研究

关键信息

据报道，在太极戟的种子发育过程中，淀粉与油脂生物合成之间存在碳竞争，但储藏动态表明，在其他种菊中没有明显的碳竞争。

抽象

种子发育过程中不同存储储备的积累可能具有竞争力。已经在Styrax tonkinensis（Pierre）Craib ex Hartwich中报道了碳竞争（即碳流入淀粉而不是油）。在这项研究中，形态发展模式和其他五种菊科植物（S. calvescens Perkins，S. dasyantha Perk。，S. faberi Perk。，S. japonicus Sieb。et Zucc。，and S.香茅冠军 超过50天进行了分析。在所有物种中，籽粒新鲜物质和干物质在发育过程中均增加，而水分含量的百分比趋势在最后一次采样日期下降至低于40％。成熟时间因物种而异，油脂，脂肪酸组成，糖，淀粉和蛋白质的进化也不同。每个籽粒中这些主要储备部分的含量随发育而增加，并且彼此之间密切相关。最终油的浓度范围为489至548 mg g ^-1，并且各物种中主要脂肪酸（棕榈酸，油酸和亚油酸）的比例相似（分别为11–15％，39–41％和43–47％） 。相反，淀粉浓度从未超过7–45 mg g ^-1，取决于物种和发育阶段。最终蛋白质浓度为165至237 mg g ^-1。在发展过程中，S。faberi可能会出现油中途积累速度减慢的情况，而其他物种中则没有。在此检查的5个气生苯乙烯属物种中，没有一个证据表明淀粉与油积累之间存在明显的碳竞争。