Gravitropism in Higher Plant Shoots

Gravitropism in higher plant shoots. VI. Changing sensitivity to auxin in gravistimulated soybean hypocotyls.

Although the Cholodny-Went model of auxin redistribution has been used to explain the transduction phase of gravitropism for over 60 years, problems are apparent, especially with dicot stems. An alternative to an auxin gradient is a physiological gradient in which lower tissues of a horizontal stem become more sensitive than upper tissues to auxin already present. Changes in tissue sensitivit...

Electrophysiology of plant gravitropism

Update on Development Gravitropism in Higher Plants

Since 1806, we have known that plant organs use gravity as a guide for growth (Knight, 1806). The gravity-directed growth process, called gravitropism, dictates upward shoot growth to ensure a proper positioning of the leaves for efficient photosynthesis and gas exchange. It also directs roots to grow downward in soil, where they can reach out to take up the water and mineral ions required for ...

Beyond the sine law of plant gravitropism.

T he great German plant physiologist Wilhelm Pfeffer rightly claimed that “no plant is entirely without the power of movement” (1). If this fact remains underappreciated, it is perhaps because plant movements typically unfold over minutes, hours, or days, and thus exceed the attention span of all but the most dedicated observer. Among the large array of plant movements, the tropisms—that is, th...

Plant shoots exhibit synchronized oscillatory motions

In animals, the ability to move has evolved as an important means of protection from predators and for enhancing nutrient uptake. In the animal kingdom, an individual's movements may become coordinated with those of other individuals that belong to the same group, which leads, for example, to the beautiful collective patterns that are observed in flocks of birds and schools of fish or in animal...