Characterization of anatomical features, developmental roadmaps, and key genes of bamboo leaf epidermis

Abstract

The exact developmental roadmaps of bamboo leaf epidermis and the regulating genes are largely unknown. In this study, we comprehensively investigated the morphological features of the leaf epidermis of bamboo, Pseudosasa japonica. We also established the developmental roadmaps of the abaxial epidermis along the linearly growing leaf. A variant of P. japonica, P. japonica var. tsutsumiana, with smaller stomata and higher stomata density, was identified. Further analysis revealed that the higher stomata density of the variant was due to the abnormal increase in stomata columns within the single stomata band. This abnormal development of stomata bands was observed as early as the guard mother cell stage in the leaf division zone (DZ). Interestingly, the developmental pattern of the single stomata was similar in P. japonica and the variant. Molecular data showed that PjDLT (Dwarf and Low Tillering) was significantly downregulated in leaves DZ of the variant. Overexpression of PjDLT in Arabidopsis and rice results in smaller plants with lower stomata density, whereas downregulation or mutation of OsDLT results in increased stomata density. Our results highlight the morphological features and developmental schedule of the leaf epidermis of bamboo and provide evidence that DLT plays an important role in regulating stomata in bamboo and rice.

Anatomical Mechanisms of Leaf Blade Morphogenesis in Sasaella kogasensis ‘Aureostriatus’

“…Su et al [48] constructed three-dimensional structural maps of the anatomies of leaves from six bamboo species. The abaxial epidermis of linearly growing leaves of Pseudosasa japonica was observed to have a division zone of approximately 10 mm, an elongation zone of approximately 29 mm, and a maturation zone, and a precise developmental cue for the abaxial epidermis was identified [49,50]. The publication of the Phyllostachys edulis genome sequence in 2018 has led to the unveiling of many genes involved in bamboo development, and the development of high-throughput technologies is further improving our understanding of the regulation of leaf growth in bamboo plants [51,52].…”