Cell wall polymers in reaction wood

In this chapter we concentrate on the structure of reaction wood and its functional properties. The fact that a lot more detailed information exists on tension wood rather than on compression wood, this is reflected in the amount of information in this chapter. During reaction wood formation major changes take place in the cell wall polymers and their distribution. For example, in a typical broadleaf tree G-layer almost pure cellulose is produced as a thick layer, while lignin is mainly present in the middle lamellae and primary cell walls. As reaction wood is formed in trees due to a new demand for strength, we have put some emphasis on the relations between structure and the imbued function of the newly formed polymeric structures. While our understanding of the signalling of reaction wood formation is still fragmentary, we have collected the existing information on this topic in Sects. 3.2.5 and 3.3.3.2.