Bordered Pit Formation in Cell Walls of Spruce Tracheids

Variance investigation on the microstructural characteristics of vessels among three lignocellulosic biomasses

Especially, the processing and utilization of biomass-based material is closely related to the vessel, e.g. the flow of vapour and additive. It is conventional that vessels in most plants can influence on water and nutrients transport between adjacent cells, which could just infer to be important in the wood-based panel industries. In this work, a complete characterization of vessels and pits is presented for three conventional biomasses in wood-based panel: poplar (Populus deltoides) (P), moso bamboo (Phyllostachys edulis) (B), and the fruit shell of oil camellia (Camellia Oleifera) (FS_OC). Every material is analyzed by combining several techniques including: light microscopy, scanning electron microscopy and surveying calculations from resin casting. The results show that among the three biomass materials, B has a significantly larger vessel width (164.8 ± 6.0 μm for B, 2.2 ± 6.2 μm for P, 10.0 ± 0.8 μm for FS_OC) and smaller inclination angle of the perforation plates (6.8° for B, 44.7° for P), which is more conductive to improving moisture transfer between the vessels. The vessel length of P varies widely from 676.8 μm to 1025.2 μm, which is related to its seasonal growth. By resin casting analysis, more differences in the morphology and distribution of pits in the vessel walls were observed between the three species. Such as, For B, there are numerous pits between vessel cells, while very few to none between vessel and parenchyma cells or fiber. In addition to pits, B and FS_OC also have spiral thickening structures on their vessel walls. The pit membrane is an elliptical shape in P, while slit-like shape in FS_OC and a combination of both elliptical and slit-like shape in bamboo. The unique microstructural characteristics of vessels is related to the individual plant growth traits, which is the basis for biomass-based material processing and utilization.

The mRNA mobileome: challenges and opportunities for deciphering signals from the noise

Organismal communication entails encoding a message that is sent over space or time to a recipient cell, where that message is decoded to activate a downstream response. Defining what qualifies as a functional signal is essential for understanding intercellular communication. In this review, we delve into what is known and unknown in the field of long-distance messenger RNA (mRNA) movement and draw inspiration from the field of information theory to provide a perspective on what defines a functional signaling molecule. Although numerous studies support the long-distance movement of hundreds to thousands of mRNAs through the plant vascular system, only a small handful of these transcripts have been associated with signaling functions. Deciphering whether mobile mRNAs generally serve a role in plant communication has been challenging, due to our current lack of understanding regarding the factors that influence mRNA mobility. Further insight into unsolved questions regarding the nature of mobile mRNAs could provide an understanding of the signaling potential of these macromolecules.

Effects on stone cell development and lignin deposition in pears by different pollinators

INTRODUCTION

The pear pulp is formed by the development of the ovary wall, which is the somatic cell of the female parent, and its genetic traits are identical to those of the female parent, so that its phenotypic traits should also be identical to those of the female parent. However, the pulp quality of most pears, especially the stone cell clusters (SCCs) number and degree of polymerization (DP), were significantly affected by the paternal type. Stone cells are formed by the deposition of lignin in parenchymal cell (PC) walls. Studies on the effect of pollination on lignin deposition and stone cell formation in pear fruit have not been reported. Methods: In this study, 'Dangshan Su' (P. bretschneideri Rehd.) was selected as the mother tree, while 'Yali' (P. bretschneideri Rehd.) and 'Wonhwang' (P. pyrifolia Nakai.) were used as the father trees to perform cross-pollination. We investigated the effects of different parents on SCCs number and DP, and lignin deposition by microscopic and ultramicroscopic observation.

RESULTS AND DISCUSSION

The results showed that the formation of SCCs proceeds was consistent in DY and DW, but the SCC number and DP in DY were higher than that in DW. Ultramicroscopy revealed that the lignification process of DY and DW were all from corner to rest regions of the compound middle lamella and the secondary wall, with lignin particles deposited along the cellulose microfibrils. They were alternatively arranged until they filled up the whole cell cavity to culminate in the formation of stone cells. However, the compactness of the wall layer of cell wall was significantly higher in DY than in DW. We also found that the pit of stone cell was predominantly single pit pair, they transported degraded material from the PCs that were beginning to lignify out of the cells. Stone cell formation and lignin deposition in pollinated pear fruit from different parents were consistent, but the DP of SCCs and the compactness of the wall layer were higher in DY than that in DW. Therefore, DY SCC had a higher ability to resist the expansion pressure of PC.