一篇英语阅读理解题 Have you ever wondered why stems(茎)grow一篇英语阅读理解题Have you ever wondered why stems(茎)grow upwards and roots downwards?Why do plants always seem to turn towards the light and climbing plants run up rathe

一篇英语阅读理解题 Have you ever wondered why stems(茎)grow一篇英语阅读理解题Have you ever wondered why stems(茎)grow upwards and roots downwards?Why do plants always seem to turn towards the light and climbing plants run up rathe
一篇英语阅读理解题 Have you ever wondered why stems(茎)grow
一篇英语阅读理解题
Have you ever wondered why stems(茎)grow upwards and roots downwards?Why do plants always seem to turn towards the light and climbing plants run up rather than down?The answer is simple:auxin(生长素),a chemical substance that controls growth in plants.
Auxin gives away its secrets
Auxin is a plant hormone(激素).Darwin was already interested in it in the 19th century.Only in recent years,however,has the hormone started to give away its secrets,thanks to intensive molecular research.Auxin is produced in the young,growing parts of plants and then transported throughout the plant—to a low­lying stem for example.The stem needs to straighten out as soon as possible to be able to absorb the topside,resulting in the underside growing faster and the stem straightening out.For the same reason,plants in front of windows will always turn to the light.This active regulation of auxin transport allows plants to take ideal advantage of local and changing conditions.
A new means of transport for auxin
The transport of auxin through the plant plays a vital role.And,from all appearances,it is not a simple matter.The researchers identified an important new link and means of transport for auxin:PILS proteins (蛋白质).PILS proteins are vital for auxin­dependent plant growth and adjust the intracellular(细胞内的)storage of the hormone.It is exactly this compartmentalizing (分类) of auxin that seems functionally important for the various developmental processes.
Growing crops more

一篇英语阅读理解题 Have you ever wondered why stems(茎)grow一篇英语阅读理解题Have you ever wondered why stems(茎)grow upwards and roots downwards?Why do plants always seem to turn towards the light and climbing plants run up rathe
The answer is simple:auxin(生长素),a chemical substance that controls growth in plants.