Comparative proteomics analyses of rhizomes and stolons in bermudagrass

As an important perennial warm-season turfgrass species, bermudagrass (Cynodon dactylon L.) form underground-growing rhizomes and aboveground-growing stolons simultaneously, making it a fast propagating clonal plant with strong regeneration ability. However, the intrinsic difference between the two types of specialized stems are still uncharacterized, especially at the molecular level. In the current study, we compared the internode proteomes of rhizomes and stolons at the same developmental stage in the bermudagrass cultivar Yangjiang using isobaric tags for relative and absolute quantitation (iTRAQ). The results indicated that 228 protein species were differentially accumulated in the two specialized stems. These DAPs comprise complex protein networks to finely regulate diverse cellular activities in the two types of specialized stems. Notably, photosynthesis and flavonoid biosynthesis were significantly regulated in stolons, whereas sucrose and starch metabolism were significantly regulated in rhizomes.

作为一种重要的多年生暖季型草坪草物种，狗牙根（bermudagrass，Cynodon dactylon L.）可同时形成地下生长的根状茎与地上生长的匍匐茎，使其成为繁殖迅速且再生能力极强的克隆植物。然而，这两类特化茎之间的内在差异仍未得到阐明，尤其是在分子层面。本研究采用同位素标记相对和绝对定量（isobaric tags for relative and absolute quantitation，iTRAQ）技术，对狗牙根品种‘阳江’同一发育阶段的根状茎与匍匐茎的节间蛋白质组进行了比较分析。结果表明，两类特化茎中共有228种蛋白质的积累量存在显著差异。这些差异积累蛋白（differentially accumulated proteins，DAPs）构成了复杂的蛋白质网络，可精细调控两类特化茎中的多种细胞活动。值得注意的是，光合作用与黄酮类生物合成在匍匐茎中受到显著调控，而蔗糖与淀粉代谢则在根状茎中受到显著调控。