查看更多>>摘要：The CONSTANS-LIKE1 (COL1) gene plays an important role in the regulation of photoperiodic flowering in plants. In this study, two COL1 homolog genes, MiCOL1A and MiCOL1B, were isolated from mango (Mangifera indica L.). The open reading frames of MiCOL1A and MiCOL1B are 852 and 822 bp in length and encode 284 and 274 amino acids, respectively. The MiCOL1A and MiCOL1B proteins contain only one CCT domain and belong to the CO/COL group IV protein family. MiCOL1A and MiCOL1B were expressed both in vegetative and reproductive organs but with expression level differences. MiCOL1A was highly expressed in juvenile and adult leaves, but MiCOL1B was highly expressed in flowers. Seasonal expression analysis showed that MiCOL1A and MiCOL1B have similar expression patterns and higher expression levels during flower induction and flower organ differentiation periods. However, MiCOL1A and MiCOL1B exhibited unstable patterns in circadian expression analysis. MiCOL1A and MiCOL1B were localized in the nucleus and had transcriptional activation activity in yeast. Overexpression of MiCOL1A and MiCOL1B resulted in significantly delayed flowering time in Arabidopsis. Furthermore, we also found that overexpression of MiCOL1A and MiCOL1B enhanced drought tolerance in transgenic Arabidopsis. The results demonstrated that MiCOL1A and MiCOL1B are not only involved in flowering regulation but also play a role in the stress response of plants.
查看更多>>摘要：The perennial herbaceous plant, Rehmannia glutinosa Libosch, is one of traditional Chinese medicines with a long history of cultivation. However, replanted disease severely affects its yield and quality in production. In this study, a specific culture device was designed to accurately isolate the root exudates of R. glutinosa. In addition, the formation mechanism of replanted diseases mediated by root exudates was deeply studied in R. glutinosa. The results indicated that root exudates have obvious allelopathic activity, furthermore, metagenomics analysis found that the exudates were found to significantly induce the proliferation of harmful pathogenic fungal and the reduction of probiotics in rhizosphere of R. glutinosa. Further analysis found that, 8,758 genes were differentially expressed in root exudate-treated R. glutinosa plants. These genes mainly involved in critical cellular processes including immune response, hormone metabolism, signaling transduction and cell membrane transport. Of which, numerous genes were found to involve in immune response, such as PR (Pathogenesis-related protein), were highly expressed in root exudate-treated plants. Transiently overexpression experiments found that a PR1 could enhance the resistance of R. glutinosa to root exudates treatment. These results indicated that the interaction between root exudates and microbes altered the expression pattern of the genes related to immune pathway and signaling transduction mediated by it. These disordered genes finally severely affected the growth and development of R. glutinosa, and eventually formed the replanted disease. This study provides a novel approach to collect root exudates and a new data basis for revealing the molecular events occurring in replanted plants.
查看更多>>摘要：Pre-mRNA splicing is an essential step during gene expression, which takes place in the spliceosome, a large dynamic ribonucleoprotein complex assembled in a stepwise manner. During the last decade, several spliceosomal mutants were functionally identified to cause a lengthened circadian period by introducing intron retention defects into circadian clock genes in Arabidopsis. However, the spliceosomal components that play opposite roles in the circadian period via alternative 3 & PRIME; splice site (Alt 3'ss) are largely unknown. Here, we demonstrated that XCT (XAP5 CIRCADIAN TIMEKEEPER) is a key spliceosomal component associated with multiple splicing factors. Moreover, genome-wide analysis revealed that inactivation of XCT particularly results in defects in Alt 3'ss recognition by RNA sequencing. Further analysis indicated that a strong alteration in the 3 & PRIME; splice sites of LHY and TIC partly accounts for the shortened circadian period of the xct mutant. Therefore, our results demonstrated that mutations in XCT shortened the circadian period partly by alternative splicing of LHY and TIC particularly in 3 & PRIME; splice site recognition, which provides new insight into the link between alternative splicing and the circadian clock.
查看更多>>摘要：Agroecosystems represent more and more a huge long-term sink for plastic compounds which inevitably undergo fragmentation, generating micro-and nano-plastics, with potential adverse effects on soil chemistry and living organisms. The present work was focused on the short-term effects of two different concentrations of polystyrene nanoplastics (PSNPs) (0.1 or 1 g L-1 suspensions) on rice seedlings starting from seed germination, hypothesizing that possible acute effects on seedlings could depend on oxidative damage trigged by PSNPs internalization. As shown by TEM analysis, PSNPs were absorbed by roots and translocated to the shoots, affected root cell ultra-structure, the germination process, seedling growth and root mitotic activity, inducing cytogenetic aberration. Treatments were not correlated with increase in oxidative stress markers, but rather with a different pattern of their localization both in roots and in shoots, impairing H2O2 homeostasis and membrane damage, despite the adequate antioxidant response recorded. The harmful effects of PSNPs on cell biology and physiology of rice seedlings could be caused not only by a direct action by the PSNPs but also by changes in the production/ diffusion of ROS at the tissue/cellular level.
查看更多>>摘要：Plants subjected to biotic or abiotic stresses produce a large amount of reactive oxygen species (ROS). If ROS cannot be cleared in time, they cause a series of harmful reactions in plants. Ascorbate peroxidase (APX) is a key enzyme that removes ROS from plant cells and plays a vital role in plant stress resistance. However, to date, no studies on APX homologs in Cryptomeria fortunei have been reported. In this study, we isolated complementary DNA (cDNA) encoding APX from C. fortunei needles, which is referred to as CfAPX, by rapid amplification of cDNA ends (RACE). The full-length CfAPX sequence was 1226 bp in length and included a 750-bp open reading frame (ORF) encoding a protein of 249 amino acids. Phylogenetic analysis showed that APXs of different plant species have been highly evolutionarily conserved. CfAPX was shown to belong to the cytoplasmic subgroup and was more closely related to GbAPX of the gymnosperm Ginkgo biloba. CfAPX showed no transcriptional activity in yeast cells but was highly expressed in cones. To better handle abiotic stresses, compared with wild-type (WT) Arabidopsis thaliana, 35S::CfAPX transgenic Arabidopsis strongly expressed CfAPX, presented increased antioxidant enzyme activities, ascorbic acid (AsA) contents, chlorophyll levels and fluorescence parameter and reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. In addition, CfAPX expression in C. fortunei was mostly upregulated under stress. In summary, CfAPX confers abiotic stress responses to plants, which provides a scientific basis for subsequent breeding for increased stress resistance in C. fortunei.
NSTL
Elsevier