Transcriptional Regulation and Signaling of Developmental Programmed Cell Death in Plants.

Developmental programmed cell death (dPCD) has multiple functions in plant growth and development, and is of great value for industrial production. Among them, wood formed by xylem dPCD is one of the most widely used natural materials. Therefore, it is crucial to explore the molecular mechanism of plant dPCD. The dPCD process is tightly regulated by genetic networks and is involved in the transduction of signaling molecules. Several key regulators have been identified in diverse organisms and individual PCD events. However, complex molecular networks controlling plant dPCD remain highly elusive, and the original triggers of this process are still unknown. This review summarizes the recent progress on the transcriptional regulation and signaling of dPCD during vegetative and reproductive development. It is hoped that this review will provide an overall view of the molecular regulation of dPCD in different developmental processes in plants and identify specific mechanisms for regulating these dPCD events. In addition, the application of plants in industrial production can be improved by manipulating dPCD in specific processes, such as xylogenesis.

[Effects of phosphorus stress on the growth and nitrogen and phosphorus absorption of different Formosan sweet gum provenances].

Aiming at the ecological value of Formosan sweet gum (Liquidambar formosana) as a pioneer species and the status of red soil phosphorus (P) deficiency, a sand culture experiment of split design was conducted to study the responses of three-leaf stage seedlings of seven Formosan sweet gum provenances from Yixing of Jiangsu, Jingxian of Anhui, Yongkang of Zhejiang, Nanchang of Jiangxi, Shaowu of Fujian, Yanping of Fujian, and Nandan of Guangxi to four levels of P (P0, P1/2, P1, P2). With increasing P stress, the biomass and the N and P absorption of test provenances decreased, whereas the utilization efficiency increased. In higher P treatments, the provenances from Nanchang and Yixing had higher biomass and higher N and P absorption but lower utilization efficiency, while the provenance from Nandan had lower N and P absorption but higher utilization efficiency. In lower P treatments, the biomass and the P absorption and utilization efficiency of the provenances from Nanchang and Nandan were all higher. All the results illustrated that the provenances with high biomass had high P absorption at high P level, and had both high P absorption and high utilization efficiency at low P level. The provenance from Nanchang could be considered to be an excellent P stress-resistant provenance, followed by that from Nandan. Phosphorus was not a limiting nutritional factor of Formosan sweet gum, biomass, leaf delta (N/P) ratio and P efficiency could be used as the indicators of P stress-tolerance of Formosan sweet gum provenances.