Wright S Y, Suner M M, Bell P J, Vaudin M, Greenland A J
ICI Seeds, Jealott's Hill Research Station, Bracknell, UK.
Plant J. 1993 Jan;3(1):41-9. doi: 10.1046/j.1365-313x.1993.t01-2-00999.x.
Differential screening of two libraries made from whole, immature maize tassels was used to isolate six cDNAs which show enhanced levels of expression in male flowers. MFS1, MFS2, MFS4, MFS10 and MFS18, which were isolated from a 5 cm tassel library, are expressed throughout tassel growth up until mature pollen is produced in the anthers. MFS14, which was isolated from a 10-12 cm tassel library, has a narrower window of expression associated with microsporogenesis and declines as mature pollen is produced. MFS18 mRNA accumulates in the glumes and in anther walls, paleas and lemmas of mature florets. MFS18 mRNA is particularly associated with the vascular bundle in the glumes and encodes a polypeptide of 12 kDa, rich in glycine, proline and serine that has similarities with other plant structural proteins. In contrast, MFS14 mRNA accumulates in the tapetum and encodes a polypeptide of 13 kDa that is rich in alanine. The MFS14 and MFS18 proteins are basic (isoelectric points of 11.56 and 9.54, respectively) and both have hydrophobic N-termini which display all the characteristics of signal peptides, indicating that these proteins may be secreted.
通过对从未成熟的完整玉米雄穗构建的两个文库进行差异筛选，分离出了六个在雄花中表达水平增强的cDNA。从5厘米雄穗文库中分离出的MFS1、MFS2、MFS4、MFS10和MFS18，在整个雄穗生长过程中直至花药中产生成熟花粉时均有表达。从10 - 12厘米雄穗文库中分离出的MFS14，其表达窗口与小孢子发生相关且较窄，随着成熟花粉的产生而下降。MFS18 mRNA在颖片、成熟小花的花药壁、内稃和外稃中积累。MFS18 mRNA尤其与颖片中的维管束相关，编码一个12 kDa的多肽，富含甘氨酸、脯氨酸和丝氨酸，与其他植物结构蛋白具有相似性。相比之下，MFS14 mRNA在绒毡层中积累，编码一个13 kDa的多肽，富含丙氨酸。MFS14和MFS18蛋白呈碱性（分别具有11.56和9.54的等电点），且都具有疏水的N端，显示出信号肽的所有特征，表明这些蛋白可能是分泌型的。
