title: Sclereids are strong enough to support the delicate corollas: experimental and computational data evidence from Camellia sinensis (L.).
abstract: Sclereids are a fundamental cell type that widely exist in higher plants and are generally thought to have a mechanical function. However, the occurrence of sclereids in the ephemeral corolla has rarely been documented and their biological significance is poorly understood. In this study, flower buds from Camellia sinensis at various ontogenetic stages were sampled, cleared, sectioned, stained, and examined using light microscopy to ascertain the morphology and distribution of sclereids and their variation. In addition, Camellia japonica plants with distinctive floral structures were investigated and compared to explore whether sclereid occurrence is associated with floral form. In particular, a computational simulation using finite element analysis was undertaken to investigate how corollas, with and without sclereids, responded to wind and rain. The results showed that sclereids have some mechanical properties that are based on their shape and distribution, which make the soft corolla strong enough to protect the inner ovary. Thus, corolla sclereids may explain how the seemingly delicate corolla performs its protective function in response to environmental stresses. These findings provide further evidence for the hypothesis that flower traits exhibit adaptive responses to abiotic factors in addition to their traditionally recognized pollinator-mediated selection.
authors.affiliation: Marine College, Shandong University at Weihai, Weihai 264209, China.|State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Marine College, Shandong University at Weihai, Weihai 264209, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Marine College, Shandong University at Weihai, Weihai 264209, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Yang
authors.affiliation: Research Center of Mechanics and Mechatronic Equipment, Shandong University at Weihai, Weihai 264209, China.
authors.forename: Yangang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Marine College, Shandong University at Weihai, Weihai 264209, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
mesh_terms: D001696:Biomechanical Phenomena; D028241:Camellia sinensis / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D035264:Flowers / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D018519:Meristem / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D054817:Pollination / Q000502:physiology; D011891:Rain; D013314:Stress, Mechanical; D014919:Wind