Plants may not have eyes and ears,but they can recognize their siblings  ,and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete  . Canadian researchers published that sea rocket,a common seashore plant,can recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soil,they "play nice" and don't send out more roots to compete.However,the moment one of the plants is thrown in with strangers,it begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil. After reading Dudley's study,Bais decided to find the method behind the sibling recognition.Working in his laboratory,Bais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experiments,young seedlings were exposed to liquid media containing the root secretions from siblings,from strangers,or only their own secretions.The length of the longest lateral   root was measured.The exposure of plants to the root secretions of strangers induced   greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorter,because so much of their energy is directed at root growth.Because siblings aren't competing against each other,their roots are often much shallower  . Biedrzycki did the _ laboratory research,observing more than 3,000 plants involved in the study every day for seven continuous days and documenting the root patterns."Arabidopsis roots are nearly translucent   when they are young and were also twisted when I removed them from plates,"Biedrzycki notes."This manuscript   is very important for my research since the focus of my thesis project is understanding the biochemical ways behind root secretions." The research also may have implications for the home gardener."Often we'll put plants in the ground next to each other and when they don't do well,we blame the local garden center where we bought them or we attribute their failure to a germ,"Bais says."But maybe there's more to it than that." What encouraged Bais to study the sibling recognition?
Sea rocket. Plants' sensing system. Biedrzycki's thesis project. Dudley's study.