文章介绍了电子税务系统的概念, X M L 规范及特点,结合目前现有的电子税务系统结构存在的缺陷,提出了一种基于 X M L 技术的电子税务系统,研究了该电子税务系统的体系结构、数据存储、操作、数据显示技术,并对其技术实现进行...文章介绍了电子税务系统的概念, X M L 规范及特点,结合目前现有的电子税务系统结构存在的缺陷,提出了一种基于 X M L 技术的电子税务系统,研究了该电子税务系统的体系结构、数据存储、操作、数据显示技术,并对其技术实现进行了阐述。展开更多
The leaves of most higher plants are polar along their adaxial-abaxial axis, and the development of the adaxial domain （upper side） and the abaxial domain （lower side） makes the leaf a highly efficient photosynthe...The leaves of most higher plants are polar along their adaxial-abaxial axis, and the development of the adaxial domain （upper side） and the abaxial domain （lower side） makes the leaf a highly efficient photosynthetic organ. It has been proposed that a hypothetical signal transported from the shoot apical meristem （SAM） to the incipient leaf primordium, or conversely, the plant hormone auxin transported from the leaf primordium to the SAM, initiates leaf adaxial-abaxial patterning. This hypothetical signal has been referred to as the Sussex signal, because the research of fan Sussex published in 1951 was the first to imply its existence. Recent results, however, have shown that auxin polar transport flanking the incipient leaf primordium, but not the Sussex signal, is the key to initiate leaf polarity. Here, we review the new findings and integrate them with other recently published results in the field of leaf development, mainly focusing on the early steps of leaf polarity establishment.展开更多
基金supported by a grant from the National Natural Science Foundation of China 31071064 to H.H.
文摘The leaves of most higher plants are polar along their adaxial-abaxial axis, and the development of the adaxial domain （upper side） and the abaxial domain （lower side） makes the leaf a highly efficient photosynthetic organ. It has been proposed that a hypothetical signal transported from the shoot apical meristem （SAM） to the incipient leaf primordium, or conversely, the plant hormone auxin transported from the leaf primordium to the SAM, initiates leaf adaxial-abaxial patterning. This hypothetical signal has been referred to as the Sussex signal, because the research of fan Sussex published in 1951 was the first to imply its existence. Recent results, however, have shown that auxin polar transport flanking the incipient leaf primordium, but not the Sussex signal, is the key to initiate leaf polarity. Here, we review the new findings and integrate them with other recently published results in the field of leaf development, mainly focusing on the early steps of leaf polarity establishment.
