软木脂是一种植物细胞间的蜡状物质，用来防止水穿越组织。普渡大学的科学家发现变异的拟南芥品种可以产生两倍的软木脂，因此他们相信调控这种物质可以使植物更好的吸收养分。相关文章发表于新一期的PLoS Genetics。
David Salt和同事发现基于软木脂浓度的特定养分进入植物根部的途径，通过调节软木脂在根部的量，植物可以更容易的吸收有益营养物质。拥有更多软木脂的植物叶中钙、锰和锌的含量更少，钠、硫和硒的含量更高。“和动物一样，植物也有选择性的摄入物质，”Salt说，“它们需要某种量的钾或氮。”它们产生的软木脂量决定它们这些选择。
Salt等人还发现这种含两倍蜡状物质的植物可以启动防萎蔫机制。因为软木脂可以限制水份吸收，植物将减少蒸腾作用，或叶子的蒸发作用。控制软木脂可能有助于开发水利用率高的植物。（生物谷Bioon.com）
生物谷推荐原始出处：
PLoS Genet 5(5): e1000492. doi:10.1371/journal.pgen.1000492
Root Suberin Forms an Extracellular Barrier That Affects Water Relations and Mineral Nutrition in Arabidopsis
Ivan Baxter1, Prashant S. Hosmani2, Ana Rus2, Brett Lahner2, Justin O. Borevitz3, Balasubramaniam Muthukumar2, Michael V. Mickelbart2, Lukas Schreiber4, Rochus B. Franke4, David E. Salt1,2*
1 Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America, 2 Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana, United States of America, 3 Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America, 4 Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model that suberin acts to form a chemical barrier limiting the extracellular, or apoplastic, transport of water and solutes in plant roots. Using the newly characterized enhanced suberin1 (esb1) mutant, we established a connection in Arabidopsis thaliana between suberin in the root and both water movement through the plant and solute accumulation in the shoot. Esb1 mutants, characterized by increased root suberin, were found to have reduced day time transpiration rates and increased water-use efficiency during their vegetative growth period. Furthermore, these changes in suberin and water transport were associated with decreases in the accumulation of Ca, Mn, and Zn and increases in the accumulation of Na, S, K, As, Se, and Mo in the shoot. Here, we present direct genetic evidence establishing that suberin in the roots plays a critical role in controlling both water and mineral ion uptake and transport to the leaves. The changes observed in the elemental accumulation in leaves are also interpreted as evidence that a significant component of the radial root transport of Ca, Mn, and Zn occurs in the apoplast.
