In C₄ plants, the enzymatic machinery underpinning photosynthesis can vary, with, for example, three distinct C₄ acid decarboxylases being used to release CO₂ in the vicinity of RuBisCO. For decades, these decarboxylases have been used to classify C₄ species into three biochemical sub-types. However, more recently the notion that C₄ species mix and match C₄ acid decarboxylases has increased in popularity and, as a consequence, the validity of specific biochemical sub-types has been questioned. Using five species from the grass tribe Paniceae, we show that, while in some species transcripts encoding multiple C₄ acid decarboxylases accumulate, in others, transcript abundance and enzyme activity is almost entirely from one decarboxylase. In addition, the development of a bundle sheath isolation procedure for a close C₃ species in the Paniceae enables the preliminary exploration of C₄ sub-type evolution.

中文翻译：

---

Paniceae 草中不同的 C4 亚型和 C3 束鞘分离

在 C ₄植物中，支持光合作用的酶机制可以变化，例如，三种不同的 C ₄酸脱羧酶用于在 RuBisCO 附近释放 CO ₂。几十年来，这些脱羧酶已被用于将 C ₄物种分为三个生化亚型。然而，最近 C ₄物种混合和匹配 C ₄酸脱羧酶的概念越来越流行，因此，特定生化亚型的有效性受到质疑。使用草部落 Paniceae 的五个物种，我们表明，而在一些物种中，编码多个 C ₄酸性脱羧酶积累，在其他情况下，转录丰度和酶活性几乎完全来自一种脱羧酶。此外，为Paniceae 中的一个紧密 C ₃物种开发的束鞘隔离程序能够对 C ₄亚型进化进行初步探索。