sentence: In fact , bacteria are not uniformly distributed across leaf surfaces : instead , they form scattered microcolonies in proximity of trichomes , stomata , epidermal cell wall junctions and grooves along veins ( Lindow and Brandl , 2003 ; Vorholt , 2012 ) , where water and nutrients are most available ( Kinkel , 1997 ; Leveau and Lindow , 2001 ; Monier and Lindow , 2004 ; Vorholt , 2012 ) .