Abortion occurs during double fertilization and ovule development in Paeonia ludlowii

Abstract

Paeonia ludlowii (Stern & Taylor) D.Y.Hong, an endangered species, is indigenous to Tibet, China and propagated only by seed under natural conditions. Its natural reproduction is constrained by low fecundity. Excess seed abortion is a key factor restricting its natural reproduction, cultivation, introduction, and protection. Understanding the specific origin and occurrence of aborted ovules is important for the protection of offspring. Using serial sectioning analysis, we studied the process of pollination and fertilization of P. ludlowii and examined the characteristics of aborted ovules, developmental differences after flowering of normal and aborted ovules, and their ratios at different positions in P. ludlowii ovaries. During pollination, fertilization, and seed development, ovule abortion was frequent, with a random abortion position. There were three types of abortion, namely, abnormal pistil, sterile ovules, and embryo and endosperm abortions. Of these, embryo and endosperm abortions could be divided into early abortion and middle abortion. The early aborted ovules stopped growing on day 12, the endoblast and endosperm in the embryo sac aborted gradually. Furthermore, the shape of the embryo sac cavity changed. The volume of aborted ovules was significantly different from that of fertile ovules. At ripening, the external morphology of different types of aborted seeds was significantly different. The possible reasons for the abortion of the ovules are also discussed.

Sporogenesis, gametophyte development and embryogenesis in Glehnia littoralis

“…Abnormal developed ovules, appeared at the stage of female gametophyte development, was characterized by small and hollow embryo sac and abnormal integument. These two conditions may be explained by an imbalance in supply to organs of different parts due to nutrient limitation of the plant [ 31 ]. (2) Seed abortion occurred at different times.…”

Transcriptome sequencing and gene expression analysis revealed early ovule abortion of Paeonia ludlowii

“…Our laboratory's preliminary experimental results showed structural differences between normal and abortion ovules from 9 DAF [36]. Therefore, we selected the ovule samples from the 9th to 17th DAF for transcriptome sequencing.…”

Transcriptomic and Metabolic Profiling Reveal the Mechanism of Ovule Development in Castanea mollissima

“…The ovule is one of the final structures formed in flowers; it contains relatively little tissue but undergoes complex developmental transformations necessary for reproduction [1]. Embryonic development is a very important step in the process of plant growth and development, but not all sexual reproduction processes in plants occur smoothly and produce reproductively capable offspring [2]. On the one hand, ovule abortion leads to a reduction in the seating rate, resulting in yield reductions [3,4].…”

“…It was reported that the VvGA3ox and VvGA2ox gene families affect ovule abortion by regulating the content of active gibberellins [15]. Downregulation of the expression of the genes encoding the ATPase PEPC and GAPDH in oil tea causes abnormalities in the cellular energy metabolism system, thereby affecting ovule development [2]. Research on the embryonic development of woody plants has remained incomplete due to the limitations posed by variable growth environments, complex genetic backgrounds, and long growth cycles.…”