Ectopic expression of the BoTFL1-like gene of Bambusa oldhamii delays blossoming in Arabidopsis thaliana and rescues the tfl1 mutant phenotype.

TERMINAL FLOWER1 (TFL1) homologous genes play major roles in maintaining vegetative growth and inflorescence meristem characteristics in various plant species; however, to date, the function of the bamboo TFL1 homologous gene has not been described. In this study, a TFL1 homologous gene was isolated from Bambusa oldhamii and designated as BoTFL1-like. Phylogenetic analysis of TFL1 homologous genes revealed that BoTFL1-like shared more than 90% identity with the TFL1 genes of other Gramineae. RT-PCR analysis showed that the expression level of BoTFL1-like in floral buds was almost 3.5 times higher than in vegetative buds. In 35S::BoTFL1-like transgenic Arabidopsis thaliana plants, the time of flowering was significantly delayed by 5 to 9 days, and development of floral buds and sepals was severely affected compared to wild type Arabidopsis plants. This suggests that the BoTFL1-like gene may play roles in flowering time and flower morphological structure in B. oldhamii. The BoTFL1-like gene driven by the 35S promoter almost fully rescued the phenotype of the tfl1 mutant apart from the number of rosette inflorescences, indicating that the function of BoTFL1-like was similar to TFL1 in Arabidopsis. We conclude the TFL1 gene function has been conserved between B. oldhamii and A. thaliana.

Fengshui forests conserve genetic diversity: a case study of Phoebe bournei (Hemsl.) Yang in southern China.

Fengshui forests (sacred groves) are important in traditional Chinese culture and home to many endangered species. These forests may provide protection for some endangered plant species outside the nature reserves, but little is known about their role in genetic conservation. Using inter-simple sequence repeat (ISSR) markers, we compared the genetic diversity of 6 populations of Phoebe bournei (Hemsl.) Yang, a commercially important woody species, which is under second-class national protection and endemic to China. Samples were collected from the nature reserves and Fengshui forests in southern China. Herein, we show that Fengshui forest populations are capable of maintaining some level of genetic diversity. For nature reserve populations, the average NA and NE were 1.58 and 1.39, respectively; and for Fengshui forests, they were 1.39 and 1.12, respectively. For nature reserve populations, Nei's gene diversity (H) and Shannon's index (I) were 0.32 and 0.11, respectively; and for Fengshui forests, they were 0.22 and 0.07, respectively. We discuss the reasons for the genetic differences between populations of the Fengshui forests and nature reserves and propose conservation strategies for the Fengshui forest.

Crossbreeding of Phyllostachys species (Poaceae) and identification of their hybrids using ISSR markers.

Crossbreeding is an efficient means to increase production and quality in plants; however, hybridization is seldom reported in bamboo. We crossbred two bamboo species Phyllostachys kwangsiensis (female parent) and Phyllostachys bambusoides (male parent) for the first time, and obtained suspected bamboo hybrids. We identified two bamboo hybrids from the above parents using PCR/ISSR. We concluded that ISSR markers are useful to identify bamboo hybrids, and that breeding between bamboo species is possible and useful.

Understanding bamboo flowering based on large-scale analysis of expressed sequence tags.

Unlike other plants, bamboo (Bambusoideae) flowering is an elusive physiological phenomena, because it is unpredictable, long-periodic, gregarious, and uncontrollable; also, bamboo plants usually die after flowering. The flowering mechanism in Arabidopsis thaliana, a eudicot model species, is well established, but it remains unknown in bamboo species. We found 4470 and 3878 expressed sequence tags in the flower bud and vegetative shoot cDNA libraries, respectively, of the bamboo species, Bambusa oldhamii. Different genes were found expressed in bamboo flower buds compared to vegetative shoots, based on the Munich Information Center for Protein Sequences functional categorization; flowering-related genes were also identified in this species. We also identified Arabidopsis flowering-specific homologs that are involved in its photoperiod in this bamboo species, along with autonomous, vernalization and gibberellin-dependent pathways, indicating that bamboos may have a similar mechanism to control floral transition. Some bamboo expressed sequence tags shared high similarity with those of rice, but others did not match any known sequences. Our data lead us to conclude that bamboo may have its own unique flowering genes. This information can help us understand bamboo flowering and provides useful experimental methods to study the mechanisms involved.