Science. 1985 Oct 25;230(4724):445-7. doi: 10.1126/science.230.4724.445.
Plant roots grow in the direction of increasing soil moisture, but studies of hydrotropism have always been difficult to interpret because of the effect of gravity. In this study it was found that roots of the mutant pea ;Ageotropum' are neither gravitropic nor phototropic, but do respond tropically to a moisture gradient, making them an ideal subject for the study of hydrotropism. When the root caps were removed, elongation was not affected but hydrotropism was blocked, suggesting that the site of sensory perception resides in the root cap.
植物的根朝着土壤湿度增加的方向生长，但由于重力的影响，向水性的研究一直难以解释。在这项研究中发现，突变豌豆“Ageotropum”的根既没有向地性也没有向光性，但对湿度梯度有向性反应，使它们成为向水性研究的理想对象。当根冠被去除时，伸长不受影响，但向水性被阻断，这表明感觉感知的部位位于根冠中。
