Dormancy is an adaptive mechanism that allows temperate deciduous plants to survive unfavorable winter conditions. In the present work, we investigated the possible function of abscisic acid (ABA) on the endodormancy process in pear. The ABA content increased during pear flower bud endodormancy establishment and decreased towards endodormancy release. In total, 39 putative genes related to ABA metabolism and signal transductions were identified from pear genome. During the para- to endodormancy transition, PpNCED-2 and PpNCED-3 had high expression levels, while PpCYP707As expression levels were low. However, during endodormancy, the expression of PpCYP707A-3 sharply increased with increasing cold accumulation. At the same time, the ABA content of pear buds declined, and the percentage of bud breaks rapidly increased. On the other hand, the expression levels of PpPYLs, PpPP2Cs, PpSnRK2s, and PpABI4/ABI5s were also changed during the pear flower bud dormancy cycle. Furthermore, exogenous ABA application to para-dormant buds significantly reduced the bud breaks and accelerated the transition to endodormancy. During the whole treatment time, the expression level of PpPP2C-12 decreased to a greater extent in ABA-treated buds than in control. However, the expression levels of PpSnRK2-1, PpSnRK2-4, and PpABI5-1 were higher in ABA-treated buds. Our results indicated that PpCYP707A-3 and PpNCEDs play pivotal roles on the regulation of endodormancy release, while ABA signal transduction pathway also appears to be involved in the process. The present work provided the basic information about the function of ABA-related genes during pear flower bud dormancy process.

https://www.mdpi.com/1422-0067/19/1/310/pdf

Abscisic Acid (ABA ) Promotes the Induction and Maintenance of Pear (Pyrus pyrifolia White Pear Group) Flower Bud Endodormancy.

The molecular mechanism regulating dormancy release in grapevine buds is as yet unclear. It has been hypothesized that (i) abscisic acid (ABA) represses bud-meristem activity; (ii) perturbation of respiration induces an interplay between ethylene and ABA metabolism, which leads to removal of repression; and (iii) gibberellin (GA)-mediated growth is resumed. The first two hypothesis have been formally supported. The current study examines the third hypothesis regarding the potential involvement of GA in dormancy release. We found that during natural dormancy induction, levels of VvGA3ox, VvGA20ox, and VvGASA2 transcripts and of GA1 were decreased. However, during dormancy release, expression of these genes was enhanced, accompanied by decreased expression of the bud-expressed GA-deactivating VvGA2ox. Despite indications for its positive role during natural dormancy release, GA application had inhibitory effects on bud break. Hydrogen cyanamide up-regulated VvGA2ox and down-regulated VvGA3ox and VvGA20ox expression, reduced GA1 levels, and partially rescued the negative effect of GA. GA had an inhibitory effect only when applied simultaneously with bud-forcing initiation. Given these results, we hypothesize that during initial activation of the dormant bud meristem, the level of GA must be restricted, but after meristem activation an increase in its level serves to enhance primordia regrowth.

Distinct gibberellin functions during and after grapevine bud dormancy release.

Grapevine immune signaling network in response to drought stress as revealed by transcriptomic analysis.

To grow or not to grow, a power-saving program induced in dormant buds.

Unveiling winter dormancy through empirical experiments

Bud dormancy is an important biological phenomenon of perennial plants that enables them to survive under harsh environmental circumstances. Grape (Vitis vinifera) is one of the most grown fruit crop worldwide; however, underlying mechanisms involved in grape bud dormancy are not yet clear. This work was aimed to explore the underlying molecular mechanism regulating bud dormancy in grape. We have performed transcriptome and differential transcript expression analyses of “Shine Muscat” grape buds using the Illumina RNA-seq system. Comparisons of transcript expression levels among three stages of dormancy, paradormancy (PD) vs endodormancy (ED), summer buds (SB) vs ED and SB vs PD, resulted in the detection of 8949, 9780 and 3938 differentially expressed transcripts, respectively. Out of approximately 78 million high-quality generated reads, 6096 transcripts were differentially expressed (log2 ratio ≥ 1, FDR ≤ 0.001). Grape reference genome was used for alignment of sequence reads and to measure the expression level of transcripts. Furthermore, findings obtained were then compared using two different databases; Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), to annotate the transcript descriptions and to assign a pathway to each transcript. KEGG analysis revealed that secondary metabolites biosynthesis and plant hormone signaling was found most enriched out of the 127 total pathways. In the comparisons of the PD vs ED and SB vs ED stages of grape buds, the gibberellin (GA) and abscisic acid (ABA) pathways were found to be the most enriched. The ABA and GA pathways were further analyzed to observe the expression pattern of differentially expressed transcripts. Transcripts related to the PP2C family (ABA pathway) were found to be up-regulated in the PD vs ED comparison and down-regulated in the SB vs ED and SB vs PD comparisons. GID1 family transcripts (GA pathway) were up-regulated while DELLA family transcripts were down-regulated during the three dormancy stages. Differentially expressed transcripts (DEGs) related to redox activity were abundant in the GO biological process category. RT-qPCR assay results for 12 selected transcripts validated the data obtained by RNA-seq. At this stage, taking into account the results obtained so far, it is possible to put forward a hypothesis for the molecular mechanism underlying grape bud dormancy, which may pave the way for ultimate improvements in the grape industry.

/pdf/comparative-rna-seq-based-transcriptomic-analysis-of-bud-2s98rjb4xz.pdf

Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape

Additional file 7: Table S7. of Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape

Carbon storage is an important component of ecosystem services. Under climate warming and human activities, land use/land cover (LULC) have been undergoing tremendous change, leading to spatio-temporal variations in carbon storage. Based on seven series of LULC data and combined with carbon module of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, spatial-temporal changes in LULC types and carbon storage were analyzed and estimated for Heilongjiang Province, Northeast China. Results show varied carbon storage among different types of LULC. Forest and cropland are the dominant LULC types in Heilongjiang Province, Northeast China, accounting for 46–49% (20.90 × 104–22.12 × 104 km2) and 30–37% (13.56 × 104–16.70 × 104 km2) of the total area. Areal extents of forest, grassland, and unused land declined from 1980 to 2015, by 1.22, 0.84, and 1.11 × 104 km2, respectively; while those of cropland and construction land expanded, by 3.14 and 0.08 × 104 km2, respectively. From 1980 to 2015, carbon storage displayed consistent change trends with those of LULC types: carbon storage of forest, grassland, and unused land decreased by 236.22, 116.61 and 21.82 × 106 Mg C, respectively; and those of cropland and construction land increased by 414.65 and 0.99 × 106 Mg C, respectively. The total carbon storage in the study region was 6,863.06 × 106–6,907.64 × 106 Mg C, for which the forest, cropland, and grassland were the major contributor (6,778.75 × 106–6,840.57 × 106 Mg C). Due to the conversion of large extents of forest, grassland, and unused land to cropland, which facilitated the formation of carbon sinks and thus enlarged the carbon storage by 45.36 × 106 Mg C from 1980 to 2015. Frequent forest fires, urban expansion, farmland reclamation, and engineering construction were the important factors of changes in the LULC, accelerating permafrost degradation and leading to obvious changes in the total carbon storage in the Heilongjiang Province, Northeast China. Therefore, the estimation of carbon storage in different LULC types can provide important data support and have important implications for evaluation of ecosystem services and carbon cycle.

Spatio-Temporal Patterns of Carbon Storage Derived Using the InVEST Model in Heilongjiang Province, Northeast China

The application of Ericoid mycorrhizal (ErM) fungi is considered to be an important strategy for increasing plant yield and drought resistance. In this study, we isolated and identified two ErM fungi that can promote the growth of lingonberry. We tried to understand the potential of these two ErM fungi to promote the growth of lingonberry and the strategies to help plants cope with water shortage. The use value of ErM fungi was evaluated by inoculating Oidiodendron maius FC (OmFC) or Lachnum pygmaeum ZL6 (LpZL6), well-watered (WW) and severe drought stress (SDS). The results showed that the mycelium of LpZL6 was denser than that of OmFC, and both ErM fungi significantly increased the biomass of lingonberry stems and roots. They also significantly increased the chlorophyll content by 65.6 and 97.8%, respectively. In addition, inoculation with LpZL6 fungi can improve drought resistance, promote root growth and increase root wet weight by 1157.6%. Drought reduced the chlorophyll content and soluble sugar content of lingonberry but increased significantly after inoculation with LpZL6. Inoculation with LpZL6 decreased lingonberry’s malondialdehyde (MDA) content but increased the superoxide dismutase (SOD) activity. Overall, these results indicated that the successful coexistence of ErM fungi and lingonberry alleviated the adverse effects of drought stress through higher secondary metabolites and photosynthetic pigment synthesis.

/pdf/lingonberry-vaccinium-vitis-idaea-l-interact-with-lachnum-2iwnavut.pdf

Lingonberry (Vaccinium vitis-idaea L.) Interact With Lachnum pygmaeum to Mitigate Drought and Promote Growth

BackgroundBud dormancy is an important biological phenomenon of perennial plants that enables them to survive under harsh environmental circumstances. Grape (Vitis vinifera) is one of the most grown fruit crop worldwide; however, underlying mechanisms involved in grape bud dormancy are not yet clear. This work was aimed to explore the underlying molecular mechanism regulating bud dormancy in grape.ResultsWe have performed transcriptome and differential transcript expression analyses of “Shine Muscat” grape buds using the Illumina RNA-seq system. Comparisons of transcript expression levels among three stages of dormancy, paradormancy (PD) vs endodormancy (ED), summer buds (SB) vs ED and SB vs PD, resulted in the detection of 8949, 9780 and 3938 differentially expressed transcripts, respectively. Out of approximately 78 million high-quality generated reads, 6096 transcripts were differentially expressed (log2 ratio ≥ 1, FDR ≤ 0.001). Grape reference genome was used for alignment of sequence reads and to measure the expression level of transcripts. Furthermore, findings obtained were then compared using two different databases; Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), to annotate the transcript descriptions and to assign a pathway to each transcript. KEGG analysis revealed that secondary metabolites biosynthesis and plant hormone signaling was found most enriched out of the 127 total pathways. In the comparisons of the PD vs ED and SB vs ED stages of grape buds, the gibberellin (GA) and abscisic acid (ABA) pathways were found to be the most enriched. The ABA and GA pathways were further analyzed to observe the expression pattern of differentially expressed transcripts. Transcripts related to the PP2C family (ABA pathway) were found to be up-regulated in the PD vs ED comparison and down-regulated in the SB vs ED and SB vs PD comparisons. GID1 family transcripts (GA pathway) were up-regulated while DELLA family transcripts were down-regulated during the three dormancy stages. Differentially expressed transcripts (DEGs) related to redox activity were abundant in the GO biological process category. RT-qPCR assay results for 12 selected transcripts validated the data obtained by RNA-seq.ConclusionAt this stage, taking into account the results obtained so far, it is possible to put forward a hypothesis for the molecular mechanism underlying grape bud dormancy, which may pave the way for ultimate improvements in the grape industry.

Long Sun

Papers

Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape

Additional file 7: Table S7. of Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape

Spatio-Temporal Patterns of Carbon Storage Derived Using the InVEST Model in Heilongjiang Province, Northeast China

Lingonberry (Vaccinium vitis-idaea L.) Interact With Lachnum pygmaeum to Mitigate Drought and Promote Growth

Additional file 3: Table S3. of Comparative RNA-seq based transcriptomic analysis of bud dormancy in grape