摘要
Once upon a time, there was an unusual corn; and un-like its normal siblings, its stalk grew towards the groundrather than in an upward direction. The sleeping stature ofthe corn was portrayed in early 1930s as 'lazy' by Jenkinsand Gerhardt [1]. Later, lazy appeared to be a fashionin the plant kingdom, found in rice, barley, tomato andseveral other species [2]. These seemingly magic spell-chanted plants have drawn considerable interests of plantbiologists and breeders for many decades. To breeders, thelazy phenotype, viewed as tillering or branching anglesof stems (or termed as culms in crop plants), represents akey characteristic important for controlling photosynthesisefficiency and planting density, and thus a crucial factor indetermining crop production [6]. Previous physiologicalstudies suggested that the prostrate or lazy phenotype wasattributed, at least in part, to the loss of gravitropism. Forexample, the rice lazyl plants are ageotropic, whereas wildtype (WT) plants are negatively geotropic [2]. Gravity plays a major role in plant morphogenesis bydetermining the directional growth of plant organs. Upongermination, shoots grow upward, capturing light, and bycontrast, roots penetrate the soil and grow downward, tak-
Once upon a time, there was an unusual corn; and unlike its normal siblings, its stalk grew towards the ground rather than in an upward direction. The sleeping stature of the corn was portrayed in early 1930s as ＂lazy＂ by Jenkins and Gerhardt. Later, lazy appeared to be a fashion in the plant kingdom, found in rice, barley, tomato and several other species . These seemingly magic spellchanted plants have drawn considerable interests of plant biologists and breeders for many decades. To breeders, the lazy phenotype, viewed as tillering or branching angles of stems （or termed as culms in crop plants）, represents a key characteristic important for controlling photosynthesis efficiency and planting density, and thus a crucial factor in determining crop production .
