scholarly journals ZmCCT regulates photoperiod-dependent flowering and response to stresses in maize

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Huihui Su ◽  
Jiachen Liang ◽  
Salah Fatouh Abou-Elwafa ◽  
Haiyang Cheng ◽  
Dandan Dou ◽  
...  

Abstract Background Appropriate flowering time is very important to the success of modern agriculture. Maize (Zea mays L.) is a major cereal crop, originated in tropical areas, with photoperiod sensitivity. Which is an important obstacle to the utilization of tropical/subtropical germplasm resources in temperate regions. However, the study on the regulation mechanism of photoperiod sensitivity of maize is still in the early stage. Although it has been previously reported that ZmCCT is involved in the photoperiod response and delays maize flowering time under long-day conditions, the underlying mechanism remains unclear. Results Here, we showed that ZmCCT overexpression delays flowering time and confers maize drought tolerance under LD conditions. Implementing the Gal4-LexA/UAS system identified that ZmCCT has a transcriptional inhibitory activity, while the yeast system showed that ZmCCT has a transcriptional activation activity. DAP-Seq analysis and EMSA indicated that ZmCCT mainly binds to promoters containing the novel motifs CAAAAATC and AAATGGTC. DAP-Seq and RNA-Seq analysis showed that ZmCCT could directly repress the expression of ZmPRR5 and ZmCOL9, and promote the expression of ZmRVE6 to delay flowering under long-day conditions. Moreover, we also demonstrated that ZmCCT directly binds to the promoters of ZmHY5, ZmMPK3, ZmVOZ1 and ZmARR16 and promotes the expression of ZmHY5 and ZmMPK3, but represses ZmVOZ1 and ZmARR16 to enhance stress resistance. Additionally, ZmCCT regulates a set of genes associated with plant development. Conclusions ZmCCT has dual functions in regulating maize flowering time and stress response under LD conditions. ZmCCT negatively regulates flowering time and enhances maize drought tolerance under LD conditions. ZmCCT represses most flowering time genes to delay flowering while promotes most stress response genes to enhance stress tolerance. Our data contribute to a comprehensive understanding of the regulatory mechanism of ZmCCT in controlling maize flowering time and stress response.

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Duwini Padukkage ◽  
Gamini Senanayake ◽  
Sudarshanee Geekiyanage

AbstractUnavailability of information on photoperiod sensitivity of traditional rice is a disadvantage in breeding rice for adaptation to changing climatic conditions and for optimum plant architecture. This experiment was conducted to address the above problem through determination of variation in days to flowering (DF) and morphological traits of twenty eight selected very early maturing Sri Lankan traditional rice accessions under three photoperiod conditions: short day (SD), day neutral (DN) and long day (LD). Although rice is considered to be a facultative short day plant, 12 accessions (2088, 2979, 4615, 3970, 4245, 2091, 3450, 3883, 4217, 6741, 3738 and 3677) flowered significantly late under SD over LD, while accession 4223 flowered significantly late under DN. Fifteen accessions (3943, 4042, 4734, 3693, 4513, 3845, 4390, 4144, 4220, 4223, 4237, 4387, Bg 300, At 308 and Bg 379-2) flowered significantly early under SD over LD. Four accessions (3457, 3884, 6305 and 4358) were non-responsive to photoperiod for flowering time. Plant height significantly increased only in accession 4217 under SD. Higher plant height under DN was obtained from At 308 and accession 3883. Photoperiod did not affect plant height in accession 4237 and Bg 379-2. LD only or both LD and DN conditions produced significantly higher plant height irrespective of photoperiod responsiveness for DF in rest 26 accessions. Variation in response to photoperiod for DF and plant architecture in very early maturing Sri Lankan rice indicates the potential diversity of genetic factors for photoperiod response for future use in rice breeding.


Author(s):  
Rongkui Han ◽  
Dean Lavelle ◽  
Maria José Truco ◽  
Richard Michelmore

Abstract Key message A population of lettuce that segregated for photoperiod sensitivity was planted under long-day and short-day conditions. Genetic mapping revealed two distinct sets of QTLs controlling daylength-independent and photoperiod-sensitive flowering time. Abstract The molecular mechanism of flowering time regulation in lettuce is of interest to both geneticists and breeders because of the extensive impact of this trait on agricultural production. Lettuce is a facultative long-day plant which changes in flowering time in response to photoperiod. Variations exist in both flowering time and the degree of photoperiod sensitivity among accessions of wild (Lactuca serriola) and cultivated (L. sativa) lettuce. An F6 population of 236 recombinant inbred lines (RILs) was previously developed from a cross between a late-flowering, photoperiod-sensitive L. serriola accession and an early-flowering, photoperiod-insensitive L. sativa accession. This population was planted under long-day (LD) and short-day (SD) conditions in a total of four field and screenhouse trials; the developmental phenotype was scored weekly in each trial. Using genotyping-by-sequencing (GBS) data of the RILs, quantitative trait loci (QTL) mapping revealed five flowering time QTLs that together explained more than 20% of the variation in flowering time under LD conditions. Using two independent statistical models to extract the photoperiod sensitivity phenotype from the LD and SD flowering time data, we identified an additional five QTLs that together explained more than 30% of the variation in photoperiod sensitivity in the population. Orthology and sequence analysis of genes within the nine QTLs revealed potential functional equivalents in the lettuce genome to the key regulators of flowering time and photoperiodism, FD and CONSTANS, respectively, in Arabidopsis.


2021 ◽  
Author(s):  
Rongkui Han ◽  
Dean Lavelle ◽  
Maria José Truco ◽  
Richard Michelmore

Abstract The molecular mechanism of flowering time regulation in lettuce is of interest to both geneticists and breeders because of the extensive impact of this trait on agricultural production. Lettuce is a facultative long-day plant which changes in flowering time in response to photoperiod. Variations exist in both flowering time and the degree of photoperiod sensitivity among accessions of wild (Lactuca serriola) and cultivated (L. sativa) lettuce. An F6 population of 236 recombinant inbred lines (RILs) was previously developed from a cross between a late-flowering, photoperiod-sensitive L. serriola accession and an early-flowering, photoperiod-insensitive L. sativa accession. This population was planted under long-day (LD) and short-day (SD) conditions in a total of four field and screenhouse trials; the developmental phenotype was scored weekly in each trial. Using genotyping-by-sequencing (GBS) data of the RILs, quantitative trait loci (QTL) mapping revealed five flowering time QTLs that together explained more than 20% of the variation in flowering time under LD conditions. Using two independent statistical models to extract the photoperiod sensitivity phenotype from the LD and SD flowering time data, we identified an additional five QTLs that together explained more than 30% of the variation in photoperiod sensitivity in the population. Orthology and sequence analysis of genes within the nine QTLs revealed potential functional equivalents in the lettuce genome to the key regulators of flowering time and photoperiodism, FD and CONSTANS respectively, in Arabidopsis.


1991 ◽  
Vol 71 (1) ◽  
pp. 87-93 ◽  
Author(s):  
D. J. Major ◽  
M. R. Hanna ◽  
B. W. Beasley

Ten cultivars of alfalfa (Medicago sativa L.) were exposed to low temperatures for varying times and to a series of photoperiods in controlled environment cabinets to determine vernalization and photoperiod responses. There was a reduction in time of 2–16 d from emergence to flowering for vernalization treatments. Vernalization treatments of less than 1 d or greater than 28 d had similar numbers of days from emergence to flowering. The photoperiod response characteristics included the basic vegetative phase (BVP), which is a juvenile phase that must be completed before the plant is responsive to photoperiod, the maximal optimal photoperiod (MOP), the photoperiod beyond which flowering occurs in a constant number of days, and photoperiod sensitivity, the number of days delay in flowering per hour increase in photoperiod. Anik and Vernal comprised a group with the longest BVP, 29.0 d; a group of six cultivars had a mean BVP of 27.6 d, and Maris Kabul and Saranac had the shortest BVP, 25.6 d. The MOP was greatest for Beaver (19 h), shortest for Vernal (17.7 h) and intermediate for the remaining cultivars (18.3 h). Alfalfa was confirmed as a long-day plant, because the time to flowering decreased as photoperiod was lengthened. This results in negative photoperiod sensitivity values. Anik, with a photoperiod sensitivity of −20.50 d h−1, was different from the rest of the cultivars, with a photoperiod sensitivity ranging from −8.51 to −5.08 d h−1. These results demonstrate that alfalfa photoperiod response is consistent with the general response observed for annual long-day species of crop plants and suggest that legume breeders may be able to incorporate specific photoperiod characteristics into alfalfa cultivars in order to optimize harvest dates. Key words: Daylength, development, flowering


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481d-481
Author(s):  
Z. Wang ◽  
M.C. Acock ◽  
B. Acock

To develop models for estimating growth, flowering time and gum yield of opium poppy, we compared variability among five cultivars (T, L, B1, B2, B3) from different latitudes in three Southeast Asian countries. Variability in the relationships between gum yield, capsule volume, and dry weight was also examined. Plants were grown in six growth chambers at a 11-, 12-, 13-, 14-, 15-, or 16-h photoperiod (PP) with a 12-h 25/20 °C thermoperiod. The main capsule was lanced for opium gum at 10, 13, and 16 d after flowering (DAF). Plants were harvested at 21 DAF and separated into leaves, stems, and capsules. Flowering time for B2 was affected least by PP and B1 the most. Flowering times for B3, L, and T were similar across the range of PPs. All cultivars showed a significant increase in flowering time from 14 to 13 h PP. Cultivars that flowered late (such as B1) had greater biomass than those that flowered earlier. However, cultivars that flowered earlier (such as L) had more dry matter partitioned into capsule than late-flowering ones. B2, B3, and L had the highest gum yields while B1 had the lowest. Positive correlations were found between gum dry weight and capsule volume (or dry weight) for T and L, but no correlations were observed between these variables for B1, B2, and B3. Our results indicated that plant dry weight varied as much as 77% and flowering time varied up to 40% even though the critical photoperiod was the same for all cultivars. The ratio of gum yield to capsule dry weight were significantly different between B1 and T.


Author(s):  
Ryan M Patrick ◽  
Xing-Qi Huang ◽  
Natalia Dudareva ◽  
Ying Li

Abstract Biosynthesis of secondary metabolites relies on primary metabolic pathways to provide precursors, energy, and cofactors, thus requiring coordinated regulation of primary and secondary metabolic networks. However, to date, it remains largely unknown how this coordination is achieved. Using Petunia hybrida flowers, which emit high levels of phenylpropanoid/benzenoid volatile organic compounds (VOCs), we uncovered genome-wide dynamic deposition of histone H3 lysine 9 acetylation (H3K9ac) during anthesis as an underlying mechanism to coordinate primary and secondary metabolic networks. The observed epigenome reprogramming is accompanied by transcriptional activation at gene loci involved in primary metabolic pathways that provide precursor phenylalanine, as well as secondary metabolic pathways to produce volatile compounds. We also observed transcriptional repression among genes involved in alternative phenylpropanoid branches that compete for metabolic precursors. We show that GNAT family histone acetyltransferase(s) (HATs) are required for the expression of genes involved in VOC biosynthesis and emission, by using chemical inhibitors of HATs, and by knocking down a specific HAT gene, ELP3, through transient RNAi. Together, our study supports that regulatory mechanisms at chromatin level may play an essential role in activating primary and secondary metabolic pathways to regulate VOC synthesis in petunia flowers.


Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3740
Author(s):  
Chunye Zhang ◽  
Ming Yang

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, followed by cholangiocarcinoma (CCA). HCC is the third most common cause of cancer death worldwide, and its incidence is rising, associated with an increased prevalence of obesity and nonalcoholic fatty liver disease (NAFLD). However, current treatment options are limited. Genetic factors and epigenetic factors, influenced by age and environment, significantly impact the initiation and progression of NAFLD-related HCC. In addition, both transcriptional factors and post-transcriptional modification are critically important for the development of HCC in the fatty liver under inflammatory and fibrotic conditions. The early diagnosis of liver cancer predicts curative treatment and longer survival. However, clinical HCC cases are commonly found in a very late stage due to the asymptomatic nature of the early stage of NAFLD-related HCC. The development of diagnostic methods and novel biomarkers, as well as the combined evaluation algorithm and artificial intelligence, support the early and precise diagnosis of NAFLD-related HCC, and timely monitoring during its progression. Treatment options for HCC and NAFLD-related HCC include immunotherapy, CAR T cell therapy, peptide treatment, bariatric surgery, anti-fibrotic treatment, and so on. Overall, the incidence of NAFLD-related HCC is increasing, and a better understanding of the underlying mechanism implicated in the progression of NAFLD-related HCC is essential for improving treatment and prognosis.


2021 ◽  
Vol 22 (13) ◽  
pp. 6952
Author(s):  
Mingxin Yu ◽  
Junling Liu ◽  
Bingshuai Du ◽  
Mengjuan Zhang ◽  
Aibin Wang ◽  
...  

NAC (NAM, ATAF1/2, and CUC2) transcription factors are ubiquitously distributed in eukaryotes and play significant roles in stress response. However, the functional verifications of NACs in Picea (P.) wilsonii remain largely uncharacterized. Here, we identified the NAC transcription factor PwNAC11 as a mediator of drought stress, which was significantly upregulated in P. wilsonii under drought and abscisic acid (ABA) treatments. Yeast two-hybrid assays showed that both the full length and C-terminal of PwNAC11 had transcriptional activation activity and PwNAC11 protein cannot form a homodimer by itself. Subcellular observation demonstrated that PwNAC11 protein was located in nucleus. The overexpression of PwNAC11 in Arabidopsis obviously improved the tolerance to drought stress but delayed flowering time under nonstress conditions. The steady-state level of antioxidant enzymes’ activities and light energy conversion efficiency were significantly increased in PwNAC11 transgenic lines under dehydration compared to wild plants. PwNAC11 transgenic lines showed hypersensitivity to ABA and PwNAC11 activated the expression of the downstream gene ERD1 by binding to ABA-responsive elements (ABREs) instead of drought-responsive elements (DREs). Genetic evidence demonstrated that PwNAC11 physically interacted with an ABA-induced protein—ABRE Binding Factor3 (ABF3)—and promoted the activation of ERD1 promoter, which implied an ABA-dependent signaling cascade controlled by PwNAC11. In addition, qRT-PCR and yeast assays showed that an ABA-independent gene—DREB2A—was also probably involved in PwNAC11-mediated drought stress response. Taken together, our results provide the evidence that PwNAC11 plays a dominant role in plants positively responding to early drought stress and ABF3 and DREB2A synergistically regulate the expression of ERD1.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Tsung-Hsien Chen ◽  
Shan-Wen Liu ◽  
Mei-Ru Chen ◽  
Kurt M Lin

Whereas aggregation of intracellular proteins was linked to the initiation of cardiac myopathy, the sequence of participating events, including myocyte apoptosis, autophagy, necrosis and fibrosis as the underlying mechanisms leading to heart failure, was not clear. Green fluorescent protein (GFP) and its derivatives induced cardiac dysfunction in mice when expressed in high quantity; however, the mechanism underlying the aggregation of fluorescent protein leading to heart failure remains unexplored.We created a transgenic mouse with switchable expression of the GFP monomer or the expression of DsRed, a red fluorescent protein (RFP) tetramer that tends to aggregate into a large protein complex. GFP mice were free of cardiac symptoms; in contrast, RFP mice with homozygous DsRed alleles developed myocyte necrosis, carditis, ventricular hypertrophy and fibrosis, left atrium thrombosis, dilated heart failure and death at the age of approximately five months. The hemizygote mice displayed similar symptoms at a later age. The expression of the microtubule-associated protein 1 light chain 3 cleaved isoform II (LC3 II) and transglutaminase 2, and the expression of many myopathy- and fibrosis-related genes were significantly induced in the hearts of two-month-old RFP mice. Together with the findings of increased autophagosomes, lysosomes and dysfunctional mitochondria, these results suggest a marked induction of myocyte autophagy and fibrosis as the main underlying mechanism of heart failure in RFP mice. Interestingly, apoptosis was not elevated in RFP hearts. One of the most up-regulated genes in the early stage RFP heart was the tissue inhibitor of matrix metalloproteinases type 1 (TIMP-1), corroborating the role of TIMP-1 in cardiac remodeling and anti-apoptotic activity. The heart-origin of the morbidity in RFP mice was confirmed by expressing DsRed tetramers specifically in cardiac tissues, and the same phenotypes as in RFP mice were observed. In summary, in cardiac myocytes under the stress of protein aggregation, strong induction of TIMP-1 and down-regulation of MMP activity may play a significant role in enhancing the synthesis of extracellular matrix, resulting in fibrosis and heart failure.


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