Comparative transcriptome analysis of the cold resistance of the sterile rice line 33S

Rice (Oryza sativa L.) is one of the most important species for food production worldwide. Low temperature is a major abiotic factor that affects rice germination and reproduction. Here, the underlying regulatory mechanism in seedlings of a TGMS variety (33S) and a cold-sensitive variety (Nipponbare) was investigated by comparative transcriptome. There were 795 differentially expressed genes (DEGs) identified only in cold-treated 33S, suggesting that 33S had a unique cold-resistance system. Functional and enrichment analysis of these DEGs revealed that, in 33S, several metabolic pathways, such as photosynthesis, amino acid metabolism, secondary metabolite biosynthesis, were significantly repressed. Moreover, pathways related to growth and development, including starch and sucrose metabolism, and DNA biosynthesis and damage response/repair, were significantly enhanced. The expression of genes related to nutrient reserve activity were significantly up-regulated in 33S. Finally, three NAC and several ERF transcription factors were predicted to be important in this transcriptional reprogramming. This present work provides valuable information for future investigations of low-temperature response mechanisms and genetic improvement of cold-tolerant rice seedlings.

Comparative Proteomics Reveals Differential Mechanism of Root Cold-resistance between Vitis. Riparia × V. Labrusca and Cabernet Sauvignon

Grapevines, containing large amounts of bioactive metabolites that offer health benefits, are widely cultivated around the world. The cold damage of growing outside with extreme low temperature during overwintering stage limits the expansion of production. Although the levels of morphological, biochemical and molecular in different Vitis species exposure to different temperatures have been investigated, differential expression of proteins in roots is still limited. Here, the roots of cold-resistant (Vitis. riparia × V. labrusca, T1) and cold-sensitive varieties (Cabernet Sauvignon, T3) at −4°C as well as of the former at −15°C (T2) were measured by iTRAQ-based proteomic analysis, expression levels of genes encoding candidate proteins were validated by qRT-PCR. The results showed that the root activity of cold-resistant variety was stronger than that of cold-sensitive variety, and it declined with the decrease of temperature. A total of 25 proteins were differentially co-expressed at T2 versus (vs) T1 and T1 vs T3, and these proteins were involved in stress response (e.g. DHN1, SHSPCP and USPCP), bio-signaling (e.g. PKCP, S/TPP and nsS/TP), metabolism (e.g. GluP, GluBE and PE), energy (e.g. AAC, AAACP and NADCP), and translation (e.g. rpL14, rpS21 and PPI). The relative expression levels of the candidate 13 genes were consistent with their fold-change values of proteins. The signature translation pattern for the roots at spatio-temporal treatments of varieties and temperatures provides insight into the differential mechanism of cold resistance of grapevines.

Breeding of winter rapeseed in VNIIMK: history and new results (review)

Breeding of winter rapeseed in the V.S. Pustovoit All-Russian Research Institute of Oil Crops was started at the end of 60th of previous century with a selection of perspective winter forms from hybrids of spring brown mustard and winter rapeseed. Heterosis in intraspecific hybrids was studied. The best intraspecific hybrids exceeded the parental forms by 20–36% by seed yield, by 20–27% by green mass yield. A possibility to create intervarietal hybrids based on heterostyly was studied. Conditions for plants acclimation to increase cold resistance of winter rapeseed were studied; methods of selection for cold resistance were developed. In 1982, the development of rapeseed and turnip rape cultivars of ‘00’ type began. To create diversity of breeding germplasm, a great amount of samples from European counties that actively deals with rapeseed breeding were included into the work. In the V.S. Pustovoit All-Russian Research Institute of Oil Crops, the methods of estimation of oil and fodder protein quality were perfected, cultivars of rapeseed and turnip rape of ‘00’ type (e.g. erucic acid free and with low glucosinolate content) were developed. As a result of breeding for oil quality, high oleic cultivars were developed, that not only improve upon the oil nutritive efficiency but open new possibilities of its technical uses due to increasing oxi- and thermostability. The first Russian high oleic winter rapeseed cultivar Olivin was developed in the V.S. Pustovoit AllRussian Research Institute of Oil Crops and introduced in the State Variety Commission in 2019. The linear cultivars of winter rapeseed were developed by inbreeding, the first interlinear hybrids – using a CMS Ogura system. One of them named Debyut was introduced in the State variety trials 2020.

Freeze-thaw Assessment of Plants Based on Envelope Analysis of Stem Volume Water Content Sequence

Background: Frost stress is an abiotic stressor for plant growth that impacts the health and the regional distribution of plants. The freeze-thaw characteristics of plants during the overwintering period help to understand relevant issues in plant physiology, including plant cold resistance and cold acclimation. Therefore, we aimed to develop a non-invasive instrument and method for accurate in situ detection of changes in stem freeze-thaw characteristics during the overwintering period. Results: A sensor was designed based on standing wave ratio method (SWR) to measure stem volume water content (StVWC). We were able to measure stem volume ice content (StVIC) and stem freeze-thaw rate of ice (StFTRI) during the overwintering period. The resolution of the StVWC sensor is less than 0.05 %, the mean absolute error and root mean square error are less than 1 %, and the dynamic response time is 0.296 s. The peak point of the daily change rate of the lower envelope of the StVWC sequence occurs when the plant enters and exits the overwintering period. The peak point can be used to determine the moment of freeze-thaw occurrence, whereas the time point corresponding to the moment of freeze-thaw coincides with the rapid transition between high and low ambient temperatures. In the field, the StVIC and StFTRI of Juniperus virginiana L., Lagerstroemia indica L. and Populus alba L. gradually increased at the beginning, fluctuated steadily during, and then gradually decreased by the end of the overwintering period. The StVIC and StFTRI also showed significant variability due to differences among the tree species and latitude.Conclusions: The StVWC sensor has good resolution, accuracy, stability, and sensitivity. The envelope changes of the StVWC sequence and the correspondence between the freeze-thaw moment and the ambient temperature indicate that the determination of the freeze-thaw moment based on the peak point of the daily change rate of the lower envelope is reliable. The results show that the sensor is able to monitor changes in the freeze-thaw characteristics of plants and effectively characterize freeze-thaw differences and cold resistance of different tree species. Furthermore, this is a cost-effective tool for monitoring freeze-thaw conditions during the overwintering period.

The cold - resistance mechanism of a mutagenic Volvariella volvacea strain VH3 with outstanding traits revealed by transcriptome profiling

Background The straw mushroom (Volvariella volvacea) is one of the important vegetables that is popular for its delicious taste. However, the straw mushroom is sensitive to low temperature, resulting in economic loss during transportation and storage. We obtained a novel straw mushroom strain, named VH3, via ultraviolet mutagenesis. Results Our study revealed that VH3 exhibited high cold resistance compared to an ordinary straw mushroom cultivar, V23. We found that the electrolyte leakages of VH3 were always significantly lower than that of V23 treated with 4 °C for 0 h, 2 h,4 h, 8 h, 16 h, and 24 h. Before cold treatment (0 h), there were no difference of MDA contents, SOD activities, and CAT activities between VH3 and V23. At the late stage (8 h, 26 h, and 24 h) of cold treatment, the MDA contents of VH3 were lower while both the SOD and CAT activities were higher than those of V23. To investigate the potential mechanisms of VH3 cold resistance, we performed transcriptome sequencing to detect the transcriptome profiling of VH3 and V23 after 0 h and 4 h cold treatment. Transcriptome sequencing revealed that 111 differentially expressed genes (DEG) between V23 (0 h) and VH3 (0 h) (V23–0_vs_VH3–0), consisting 50 up-regulated and 61 down-regulated DEGs. A total of 117 DEGs were obtained between V23 (4 h) and VH3(4 h) (V23–4_vs_VH3–4), containing 94 up-regulated and 23 down-regulated DEGs. Among these DEGs, VVO_00021 and VVO_00017 were up-regulated while VVO_00003, VVO_00004, VVO_00010, and VVO_00030 were down-regulated in V23–0_vs_VH3–0 and VH3–4_vs_V23–4. KEGG and GO analysis revealed that the 6 DEGs were annotated to pathways related to cold stress. Besides, the GA3 content was also decreased in VH3. Conclusions Collectively, our study first revealed that the increased cold resistance of VH3 might be caused by the expression change of VVO_00003, VVO_00004, VVO_00017, VVO_00021, and VVO_00030, and decreased GA3.

Survey of Overwintering Trait in Chinese Rice Cultivars (Oryza Sativa L)

Overwintering (OW) rice can survive through the natural cold-winter field environment, exhibit a strong root system activity, sprout from rice tillering node in the following spring, and apparently reveal the cold resistance of rice during the whole growth stage. The successful utilization of cold-resistant rice is the most economical strategy for the cold-resistant rice cultivar breeding. This work aims to identify the OW rice for the future development of cold-resistant cultivars. Altogether 1034 Chinese rice cultivars were evaluated for their responses to low temperatures under the natural field cold-winter environment. The heading date (HD, d) and plant height (PH, cm) of 1034 rice cultivars ranged from 65 to 140 d in 2019, 65 to 150 d in 2020, ranged from 60 to 140 cm in 2019, 60 to 150 cm in 2020, and displayed slight difference between 2019 and 2020. Among them, altogether 262 (25.34%) Japonica rice cultivars could withstand cold to 4°C in December 2019 and distributed in 13 provinces of China, survive through the natural cold-winter field environment, and sprout from rice tillering node in March 2020. Only 24 (2.32%) japonica rice cultivars with resistance to 0°C in January 2021 distributed in seven provinces of China could also sprout from rice tillering node in March 2021. The present cold-resistant rice cultivars will provide beneficial breeding germplasm for future cold-resistant rice breeding and new strategies in elucidating the molecular mechanism of the cold resistance of rice.