Laboratory of Anatomy and Morphology, V. L. Komarov Botanical Institute of Russian Academy of Sciences, Prof. Popov Street 2, 197376, St. Petersburg, Russia.
Ann Bot. 2011 Feb;107(2):269-83. doi: 10.1093/aob/mcq239. Epub 2010 Dec 8.
Cleomaceae is one of 19 angiosperm families in which C(4) photosynthesis has been reported. The aim of the study was to determine the type, and diversity, of structural and functional forms of C(4) in genus Cleome. Methods Plants of Cleome species were grown from seeds, and leaves were subjected to carbon isotope analysis, light and scanning electron microscopy, western blot analysis of proteins, and in situ immunolocalization for ribulose bisphosphate carboxylase oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC).
Three species with C(4)-type carbon isotope values occurring in separate lineages in the genus (Cleome angustifolia, C. gynandra and C. oxalidea) were shown to have features of C(4) photosynthesis in leaves and cotyledons. Immunolocalization studies show that PEPC is localized in mesophyll (M) cells and Rubisco is selectively localized in bundle sheath (BS) cells in leaves and cotyledons, characteristic of species with Kranz anatomy. Analyses of leaves for key photosynthetic enzymes show they have high expression of markers for the C(4) cycle (compared with the C(3)-C(4) intermediate C. paradoxa and the C(3) species C. africana). All three are biochemically NAD-malic enzyme sub-type, with higher granal development in BS than in M chloroplasts, characteristic of this biochemical sub-type. Cleome gynandra and C. oxalidea have atriplicoid-type Kranz anatomy with multiple simple Kranz units around individual veins. However, C. angustifolia anatomy is represented by a double layer of concentric chlorenchyma forming a single compound Kranz unit by surrounding all the vascular bundles and water storage cells.
NAD-malic enzyme-type C(4) photosynthesis evolved multiple times in the family Cleomaceae, twice with atriplicoid-type anatomy in compound leaves having flat, broad leaflets in the pantropical species C. gynandra and the Australian species C. oxalidea, and once by forming a single Kranz unit in compound leaves with semi-terete leaflets in the African species C. angustifolia. The leaf morphology of C. angustifolia, which is similar to that of the sister, C(3)-C(4) intermediate African species C. paradoxa, suggests adaptation of this lineage to arid environments, which is supported by biogeographical information.
Cleomaceae 是报告存在 C(4)光合作用的 19 个被子植物科之一。本研究的目的是确定 Cleome 属中 C(4)的结构和功能形式的类型和多样性。方法：从种子中种植 Cleome 种的植物，对叶片进行碳同位素分析、光和扫描电子显微镜分析、蛋白质的 Western blot 分析以及用于核酮糖二磷酸羧化酶加氧酶（Rubisco）和磷酸烯醇丙酮酸羧化酶（PEPC）的原位免疫定位。
在属中（Cleome angustifolia、C. gynandra 和 C. oxalidea）分别处于不同谱系的三个种具有 C(4)-型碳同位素值，其叶片和子叶中具有 C(4)光合作用的特征。免疫定位研究表明，PEPC 定位于叶肉（M）细胞，Rubisco 选择性定位于叶片和子叶的束鞘（BS）细胞，这是具有 Kranz 解剖结构的物种的特征。对叶片中关键光合作用酶的分析表明，与 C(3)-C(4)中间种 C. paradoxa 和 C(3)种 C. africana 相比，它们具有高表达的 C(4)循环标记物。所有三种都是生物化学 NAD-苹果酸酶亚型，BS 中的粒状发育高于 M 叶绿体，这是该生化亚型的特征。Cleome gynandra 和 C. oxalidea 具有三裂叶型 Kranz 解剖结构，每个静脉周围有多个简单的 Kranz 单位。然而，Cleome angustifolia 的解剖结构由两层同心的绿色组织组成，通过包围所有维管束和储水细胞，形成单个复合 Kranz 单位。
NAD-苹果酸酶型 C(4)光合作用在 Cleomaceae 科中多次进化，两次在热带物种 C. gynandra 和澳大利亚物种 C. oxalidea 的复叶中具有三裂叶型解剖结构，其复叶具有扁平、宽阔的小叶，一次在非洲物种 C. angustifolia 的复叶中形成单个 Kranz 单位，其复叶具有半圆柱形的小叶。Cleome angustifolia 的叶片形态与姐妹种、C(3)-C(4)中间非洲种 C. paradoxa 的叶片形态相似，表明该谱系适应了干旱环境，这得到了生物地理信息的支持。
