Plants may not have eyes and earsbut they can recognize their siblings (兄弟姐妹)and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete (分泌)

Canadian researchers published that sea rocketa common seashore plantcan recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soilthey “play nice” and don’t send out more roots to compete.Howeverthe moment one of the plants is thrown in with strangersit begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil.

After reading Dudley’s studyBais decided to find the method behind the sibling recognition.Working in his laboratoryBais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experimentsyoung seedlings were exposed to liquid media containing the root secretions from siblingsfrom strangersor only their own secretions.The length of the longest lateral (侧面的) root was measured.The exposure of plants to the root secretions of strangers induced (引诱) greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorterbecause so much of their energy is directed at root growth.Because siblings aren’t competing against each othertheir roots are often much shallower (浅的)

Biedrzycki did the painstaking laboratory researchobserving 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 (半透明的) when they are young and were also twisted when I removed them from plates”Biedrzycki notes.“This manuscript (手稿) 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 wellwe 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.”

1.Which of the following would be the best title for this passage?

AA Great Biology Researcher

BPlants Recognize Their Siblings

CPlants’ Roots and Secretions

DA Research on Plants

2. What encouraged Bais to study the sibling recognition?

ASea rocket.

BPlants’ sensing system.

CBiedrzycki’s thesis project.

DDudley’s study.

3. What does the underlined word “painstaking” in Paragraph 4 probably mean?

AImportant.? BAdventurous.

CCareful.? DHard?working.

4.What can we infer from the last paragraph?

AThe local garden center should be blamed when plants can’t grow well.

BThe local garden center often sells low quality seeds to customers.

CPlants in the home garden can’t grow well because of the germ and seeds.

DCompeting against strangersplants in the home garden can’t grow well.

 

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