Hochholdinger Frank, Guo Ling, Schnable Patrick S
Department of Agronomy, Iowa State University, Ames, IA 50011-3650, USA.
Plant Mol Biol. 2004 Oct;56(3):397-412. doi: 10.1007/s11103-004-3476-9.
Lateral roots are initiated from the pericycle cells of other types of roots and remain in contact with these roots throughout their life span. Although this physical contact has the potential to permit the exchange of signals, little is known about the flow of information from the lateral roots to the primary root. To begin to study these interactions the proteome of the primary root system of the maize (Zea mays L.) lrt1 mutant, which does not initiate lateral roots, was compared with the corresponding proteome of wild-type seedlings 9 days after germination. Approximately 150 soluble root proteins were resolved by two-dimensional electrophoresis and analyzed by MALDI-ToF mass spectrometry and database searching. The 96 most abundant proteins from a pH 4-7 gradient were analyzed; 67 proteins representing 47 different Genbank accessions were identified. Interestingly, 10 (15/150) of the detected proteins were preferentially expressed in lrt1 roots that lack lateral roots. Eight of these lrt1-specific proteins were identified and four are involved in lignin metabolism. This study demonstrates for the first time the influence of lateral roots on the proteome of the primary root system. To our knowledge this is the first study to demonstrate an interaction between two plant organs (viz., lateral and primary roots) at the level of the proteome.
侧根由其他类型根的中柱鞘细胞起始，并在其整个生命周期中与这些根保持接触。尽管这种物理接触有可能允许信号交换，但关于从侧根到主根的信息流却知之甚少。为了开始研究这些相互作用，将不产生侧根的玉米（Zea mays L.）lrt1突变体主根系的蛋白质组与萌发9天后野生型幼苗的相应蛋白质组进行了比较。通过二维电泳分离出约150种可溶性根蛋白，并通过基质辅助激光解吸电离飞行时间质谱（MALDI-ToF）和数据库搜索进行分析。分析了pH 4 - 7梯度下96种最丰富的蛋白质；鉴定出代表47个不同Genbank登录号的67种蛋白质。有趣的是，所检测到的蛋白质中有10种（150种中的15种）在缺乏侧根的lrt1根中优先表达。鉴定出其中8种lrt1特异性蛋白质，4种参与木质素代谢。这项研究首次证明了侧根对主根系蛋白质组的影响。据我们所知，这是第一项在蛋白质组水平上证明两种植物器官（即侧根和主根）之间相互作用的研究。
