Hakea prostrata R.Br. (Proteaceae) shows a ‘delayed greening’ strategy of leaf development characterised by reddish young leaves that become green as they mature. This trait may contribute to efficient use of phosphorus (P) during leaf development by first investing P in the development of leaf structure followed by maturation of the photosynthetic machinery. In this study, we investigated the properties of delayed greening in a highly P-efficient species to enhance our understanding of the ecological significance of this trait as a nutrient-saving and photoprotective strategy. In glasshouse-grown plants, we assessed foliar pigments, fatty acids and nutrient composition across five leaf developmental stages. Young leaves had higher concentrations of anthocyanin, P, nitrogen (N), copper (Cu), xanthophyll-cycle pigments and saturated fatty acids than mature leaves. As leaves developed, the concentration of anthocyanins decreased, whereas that of chlorophyll and the double bond index of fatty acids increased. In mature leaves, ~60% of the fatty acids was α-linolenic acid (C18:3 n-3). Mature leaves also had higher concentrations of aluminium (Al), calcium (Ca) and manganese (Mn) than young leaves. We conclude that delayed greening in H. prostrata is a strategy that saves P as well as N and Cu through sequential allocation of these resources, first to cell production and structural development, and then to supplement chloroplast development. This strategy also protects young leaves against photodamage and oxidative stress during leaf expansion under high-light conditions.

竹布朗 （Proteaceae）显示了一种叶片发育的“延迟绿化”策略，其特征是红色的幼叶随着成熟而变绿。通过首先在叶片结构的发育中投入磷，然后使光合机械成熟，此性状可能有助于叶片发育过程中磷（P）的有效利用。在这项研究中，我们调查了高磷效率物种中延迟绿化的特性，以增强我们对该特性作为养分和光保护策略的生态意义的理解。在温室种植的植物中，我们评估了五个叶片发育阶段的叶色素，脂肪酸和营养成分。幼叶的花色苷，磷，氮（N），铜（Cu），叶黄素循环色素和饱和脂肪酸的浓度高于成熟叶。随着叶片的发育，花色苷浓度降低，而叶绿素浓度和脂肪酸双键指数增加。在成熟叶片中，约60％的脂肪酸​​为α-亚麻酸（C18：3 n-3）。成熟的叶片也比年轻的叶片具有更高的铝（Al），钙（Ca）和锰（Mn）浓度。我们得出的结论是，H. prostrata是一种通过依次分配这些资源来节省P以及N和Cu的策略，首先用于细胞生产和结构开发，然后用于补充叶绿体的开发。这种策略还可以保护嫩叶在强光条件下的叶片膨胀过程中免受光害和氧化胁迫。