A novel ERF transcription factor, CmERF12, negatively influences chrysanthemum embryo development

Embryo abortion often occurs during distant hybridization events. Apetala 2/ethylene-responsive factor (AP2/ERF) proteins are key transcription factor (TF) regulators of plant development and stress resistance, but their roles in hybrid embryo development are poorly understood. We isolated a novel AP2/ERF TF, CmERF12, from chrysanthemum and showed that it adversely affects embryo development during distant hybridization. Transcriptome and real-time quantitative PCR data demonstrated that CmERF12 is expressed at significantly higher levels in aborted ovaries compared with normal ovaries. CmERF12 localizes to the cell nucleus and contains a conserved EAR motif that mediates its transcription repressor function in yeast and plant cells. We generated an amiR-CmERF12 transgenic Chrysanthemum morifolium (C.m.) var. ‘Yuhualuoying’ and conducted distant hybridization with the wild-type tetraploid, Chrysanthemum nankingense (C.n.), revealing that CmERF12 knockdown significantly promoted embryo development and increased the seed setting rates during hybridization. The expression of various embryo development-related genes was up-regulated in developing ovaries from the ♀amiR-CmERF12-C.m. × ♂C.n. cross. Furthermore, CmERF12 directly interacted with CmSUF4 and significantly reduced its ability to activate its target gene CmEC1. Overall, we invented an original method to overcome plant distant hybridization barriers and unraveled the mechanism by which CmERF12 negatively affects chrysanthemum embryo development.

Progesterone promotes fetal growth in a restricted interspecies gestation (Ovis canadensis x Ovis aries)

Progesterone promotes foetal growth in a restricted interspecies gestation (Ovis canadensis × Ovis aries). Veterinaria México OA. 2018;5(3).Gestations between bighorn (Ovis canadensis) and domestic sheep (O. aries) can be considered for ex situ conservation of bighorn. In the first experiment, domestic sheep were inseminated with bighorn or domestic semen. Bighorn inseminated sheep showed lower fertility than domestic inseminated sheep (40% vs. 65%, p = 0.11). Bighorn inseminated sheep had longer gestation periods (152.13 days vs. 146.54 days, p < 0.001) and lower progesterone levels during the last third. Hybrid lambs weighed less than domestic lambs (2.46 kg vs. 5.10 kg, p < 0.001). Their placentas were not as long (48.67 cm vs. 72.17 cm, p < 0.001), were less wide (17.83 cm vs. 23.83 cm, p < 0.001), and the weight of cotyledons was lower (1.50 g vs. 3.20 g, p < 0.001). In the second experiment, hybrid embryos (O. canadensis × O. aries) were transferred into domestic recipients, and pregnant ewes were divided into the treated group, which had a progesterone daily dose of 25 mg from weeks 7 to 20, and the non treated group. Gestation in domestic sheep that received one hybrid embryo and progesterone reached 152.60 days, which was similar to the 153.33 days (p = 0.51) in the non treated sheep. Hybrid offspring of the group treated with progesterone were heavier, 3.41 kg, than the control, 2.21 kg (p < 0.001), and their placentas were longer (71.20 vs. 50.83 cm, p = 0.002). Although progesterone levels were lower in domestic females inseminated with bighorn and in the recipients of hybrid embryos, it is possible to establish pregnancies between both species and the birth of viable offspring. The administration of progesterone during gestation increases the length of the placenta and promotes higher birth weights of hybrids.Figure 1. Progesterone (ng/mL) in interspecies gestations (O. c. mexicana × O. aries, n = 6) and intraspecies gestations (O. aries × O. aries, n = 6).*Statistically different values (p < 0.01).

THE ROLE OF NAA, GA3, ACTIVATED CHARCOAL, AND SUCROSE ON ZYGOTIC EMBRYOS CULTURE OF HYBRID OG OPEN POLLINATED CLONE (Elaeis guineensis JACQ. X Elaeis oleifera)

Oil palm OG hybrid genetic potentials are high in term of vegetative and generative traits, such as: low height increment, compact palm, high free fatty acid and high carotenes. However, OG hybrid reproduction is hindered due to its low germination rate. So, alternative method for germination is needed, which is in vitro embryo zygotic culture. This study objective was to reveal the best medium composition for OG hybrid embryo culture by modificated several oil palm basic medium from oil palm tissue culture protocol and to understand the role of plant growth regulators, activated charcoal, and sucrose on in vitro growth and development of OG hybrid embryo. The design used was Completely Randomized Design (CRD) with 16 replication and 4 embryos for each replicates, while the treatments were: A1 = M129 (control); A2 = M129 + activated charcoal; A3 = M129+ activated charcoal + sucrose; A4 = ½ M129 + activated charcoal + sucrose; A5 = M129 + GA3 ; and A6 = M129 + GA3 + NAA. From the study we found that the best medium for OG hybrid open pollinated clone's embryo culture was M129 with GA3 and NAA (A6). This medium gave percentage of in vitro germination up to 14.06%, and later on the plantlets from this medium gave the best vegetative growth performance such as high number of leaves and primer roots.

THE ROLE OF NAA, GA3, ACTIVATED CHARCOAL, AND SUCROSE ON ZYGOTIC EMBRYOS CULTURE OF HYBRID OG OPEN POLLINATED CLONE (Elaeis guineensis JACQ. X Elaeis oleifera)

Oil palm OG hybrid genetic potentials are high in term of vegetative and generative traits, such as: low height increment, compact palm, high free fatty acid and high carotenes. However, OG hybrid reproduction is hindered due to its low germination rate. So, alternative method for germination is needed, which is in vitro embryo zygotic culture. This study objective was to reveal the best medium composition for OG hybrid embryo culture by modificated several oil palm basic medium from oil palm tissue culture protocol and to understand the role of plant growth regulators, activated charcoal, and sucrose on in vitro growth and development of OG hybrid embryo. The design used was Completely Randomized Design (CRD) with 16 replication and 4 embryos for each replicates, while the treatments were: A1 = M129 (control); A2 = M129 + activated charcoal; A3 = M129+ activated charcoal + sucrose; A4 = ½ M129 + activated charcoal + sucrose; A5 = M129 + GA3 ; and A6 = M129 + GA3 + NAA. From the study we found that the best medium for OG hybrid open pollinated clone's embryo culture was M129 with GA3 and NAA (A6). This medium gave percentage of in vitro germination up to 14.06%, and later on the plantlets from this medium gave the best vegetative growth performance such as high number of leaves and primer roots.