Biological characters of root border cells development in maize (Zea mays)

Abstract

The new inbred line Xiaohuangbaogu was used to investigate biological characters of root Border Cells (BCs) development in maize. The results showed that, maize border cells adnated on the 1-2 mm region of root cap, the shape was various, round, elliptical, bacilliform and so forth. The root cap PME activity, BCs number and viability varied with the primary root elongation and the general variation trend of the three traits was first up and then down. The PME activity was highest at 28.23 umol IT root cap-1 h-1 when the primary root was 1 cm long. Root border cells developed synchronously with radicle growing, the number increased with primary root elongation, when the root was 2 cm length, the number reached a maximum of 4367, the maximum viability was about 90% when the root was 1.0 cm in length, the average viability was 76.16%. The aerial root border cells were smaller and fewer, but the viability was higher, the average BCs number was 2092 when the root was 1-4 cm in length and the average viability was 86.21 %; low temperature was beneficial to maintain the detached BCs activity, the relative viabilities were both higher than 97% if the detached BCs were standing at 5 or 10°C for one day, while it was significantly different 4 days later, the relative viability at 5°C was still high up to 46.05% 5 days later, but at 10°C was as low as 13.50%. The 20/25°C was suitable for maize BCs redevelopment, high temperature 30°C promoted border cells to regenerate rapidly in 12-24 h. BCs number increased if root suffered from drought stress, but there was no obvious change in viability. It is possible that the increased border cells play an important role in reducing adversity damage to roots while maize is suffering from low temperature or drought stress. © 2014 Asian Network for Scientific Information.