Genome-wide identification and expression analysis of the coronatine-insensitive 1 (COI1) gene family in response to biotic and abiotic stresses in Saccharum

Background The coronatine insensitive 1 (COI1) gene is the core member of jasmonate signaling pathway, which is closely related to plant biotic and abiotic resistance. However, there have been no reports on COI1 in sugarcane (Sacharum spp.). Hence, systematically investigating the characteristics of the COI1 multigene family in sugarcane can provide a means to study and manipulate the jasmonic acid signaling pathway. Results A total of 156 COI1 proteins were obtained from the genomes of 19 land plants, while none were obtained from five algae species. A phylogenetic tree demonstrated that these COI1 proteins were classified into four groups, while 31 proteins of SsCOI1 from Saccharum spontaneum, SbCOI1 from Sorghum bicolor, and ShCOI1 from Saccharum spp. hybrid cultivar R570 clustered into three groups. Synteny analysis and duplication patterns revealed that COI1 genes expanded through various genome replication events and could have experienced strong purifying selective pressure during evolution in S. spontaneum, S. bicolor, and R570. An investigation of cis-acting elements suggests that COI1 genes may be involved in plant growth and development and response to various stresses. Expression analysis implied that 21 SsCOI1 genes were constitutively expressed, and had positive responses to drought, cold, and Sporisorium scitamineum stresses with different expression patterns. Among them, seven SsCOI1 haplotype genes may play different roles in response to methyl jasmonate. Furthermore, the ShCOI1–4, ShCOI1–5, and ShCOI1–6 genes were cloned from Saccharum spp. hybrid cultivar ROC22. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that these three ShCOI1 genes had divergent expression profiles in response to salicylic acid, abscisic acid, polyethylene glycol, cold, and S. scitamineum. Conclusions These results suggest that COI1 genes may act in sugarcane growth, development, and response to various stresses via different regulatory mechanisms, which laying a foundation for the functional identification of the sugarcane COI1 gene.

Peeling Affects the Nutritional Properties of Carrot Genotypes

Peeling may result in changes in carrot’s nutritional properties; therefore, the present study focused on its effect on the retention of principal nutrients (minerals, sugars, organic acids) and antioxidants (carotenoids and phenols) in the peeled roots of two landraces (‘Carota a punta lunga’—CPL and ‘Carota a punta tonda’—CPT) and a hybrid cultivar (‘Presto’) grown in the area of the “Salterns of Margherita di Savoia” area (Puglia region). The peel had a higher concentration of cations (+92%), organic acids (+103%), carotenoids (+42%), and phenolic acids (seven times) than root flesh. For each chemical class, the most abundant components were K, malic acid, ß-carotene, and chlorogenic acid, respectively. The two landraces stand out for the accumulation of the phenolic acids and ß-carotene, whereas the peel of ‘Presto’ was distinguished by the concentration of Ca and ascorbic and pyruvic acids. The root flesh had a greater accumulation of simple sugars, nitrate (mainly in CPL), oxalic acid, and in particular in the flesh of ‘Presto’, of Na and Cl. For local varieties, peel removal seems to impact the nutritional and antioxidative properties of carrots more consistently compared to the advanced cultivar, since it represents on average 21% and 59% of the total carotenoids and phenols, respectively, of the intact roots.

Identification of Heterotic Loci with Desirable Allelic Interaction to Increase Yield in Rice

Heterosis denotes the superiority of a hybrid plant over its parents. The use of heterosis has contributed significantly to yield improvement in crops. However, the genetic and molecular bases on heterosis are not fully understood. A large number of heterotic loci were identified for 12 yield-related traits in one parental population of chromosome segment substitution lines (CSSLs) and two test populations, which were interconnected by CSSLs derived from two rice genome-sequenced cultivars, Nipponbare and Zhenshan 97. Seventy-five heterotic loci were identified in both homozygous background of Zhenshan 97 and heterogeneous background of an elite hybrid cultivar Shanyou 63. Among the detected loci, at least 11 were colocalized in the same regions encompassing previously reported heterosis-associated genes. Furthermore, a heterotic locus Ghd8NIP for yield advantage was verified using transgenic experiments. Various allelic interaction at Ghd8 exhibited different heterosis levels in hetero-allelic combinations of five near-isogenic lines that contain a particular allele. The significant overdominance effects from some hetero-allelic combinations were found to improve yield heterosis in hybrid cultivars. Our findings support the role of allelic interaction at heterotic loci in the improvement of yield potential, which will be helpful for dissecting the genetic basis of heterosis and provide an optional strategy for the allele replacement in molecular breeding programs in hybrid rice.

The Influence of Biostimulants on Tomato Plants Cultivated under Hydroponic Systems

Two biostimulants, RutfarmMaxifol (Ascophyllum nodosum extract 17.5%, amino acids, macro- and microelements, Agromaster, Russia) and Radifarm (polysaccharides, glycosides, amino acids, and micro-elements; Valagro, Italy), were applied at different concentrations on tomato plants of the hybrid cultivar ‘Merlice’, grown under a hydroponic system. Biostimulants were applied in the form of seed soaking and twice as foliar sprayings at flowering and at the initial fruit development stages. Biostimulants were applied as water solutions at concentrations of 2.5, 5.0, and 7.5 mg·L−1. Plant growth, productivity, and fruit quality parameters were determined at three points: 35, 70, and 105 days after seeding. All biostimulant treatments resulted in higher values of growth parameters and yield productivity in relation to the control. The application of biostimulants improved the parameters of the fruits’ quality by increasing the total soluble solids and antioxidants, ascorbic acid, and carotenoid contents but it did not affect tomato fruit acidity; therefore, tomato fruits from the treated plants were tastier than those from control.

Sex structure of hemp convergent hybrids

Inbreeding and its extreme form (self-pollination) are an effective method for stabilizing the monoecious traits of industrial hemp. The hybrids with self-pollinated lines as the components of which, in most cases, were characterized by a better sex composition than the output cultivar forms, and the absence of male plants. The number of monoecious feminized plant (the main sexual type of modern varieties) in hybrids created as a result of crossing in the directions of vertical convergence was from 54.2 to 100.0 %, and in hybrids created by crossing in horizontal convergence it was from 37.7 to 100.0 %. The use of hybridization in the directions of vertical and horizontal convergence is advisable in the breeding of industrial hemp, especially for obtaining a starting material with a stable trait of monoecious, with high plant biomass, fber content and seed productivity. We recommend the following crosses: the frst and third generations of simple linear-varietal hybrids of various ecological-geographical types, related to one of the parental forms (F1 × F3) (i); crossing of simple interlinear hybrids of various ecological-geographical types with an inbred line of the Central European type of a later generation from self-pollination (interline hybrid × self-pollinated line) (ii); reciprocal crosses of simple interlinear hybrids of various ecological-geographical types with the original cultivar of a self-pollinated line of the middle European type (interline hybrid × cultivar and cultivar × interline hybrid) (iii); crossing of simple linear-varietal and intervarietal hybrids of the frst generation, related in one of the parental forms (iiii). The consistent use of crossbreeding, inbreeding (or divergence), hybridization (or crossing in the vertical and horizontal convergence directions) has created heterotic hemp forms with stable productive potential, homogeneous sex structure, and non-psychotropic properties. The created variety ‘Aurora’ is an example of an innovative breeding method. Key words: hemp, breeding, sex, monoecious, crossbreeding, inbreeding, divergence, convergence, hybrid, productivity.

Elucidation of molecular and hormonal background of early growth cessation and endodormancy induction in two contrasting Populus hybrid cultivars

Background Over the life cycle of perennial trees, the dormant state enables the avoidance of abiotic stress conditions. The growth cycle can be partitioned into induction, maintenance and release and is controlled by complex interactions between many endogenous and environmental factors. While phytohormones have long been linked with dormancy, there is increasing evidence of regulation by DAM and CBF genes. To reveal whether the expression kinetics of CBFs and their target PtDAM1 is related to growth cessation and endodormancy induction in Populus, two hybrid poplar cultivars were studied which had known differential responses to dormancy inducing conditions. Results Growth cessation, dormancy status and expression of six PtCBFs and PtDAM1 were analyzed. The ‘Okanese’ hybrid cultivar ceased growth rapidly, was able to reach endodormancy, and exhibited a significant increase of several PtCBF transcripts in the buds on the 10th day. The ‘Walker’ cultivar had delayed growth cessation, was unable to enter endodormancy, and showed much lower CBF expression in buds. Expression of PtDAM1 peaked on the 10th day only in the buds of ‘Okanese’. In addition, PtDAM1 was not expressed in the leaves of either cultivar while leaf CBFs expression pattern was several fold higher in ‘Walker’, peaking at day 1. Leaf phytohormones in both cultivars followed similar profiles during growth cessation but differentiated based on cytokinins which were largely reduced, while the Ox-IAA and iP7G increased in ‘Okanese’ compared to ‘Walker’. Surprisingly, ABA concentration was reduced in leaves of both cultivars. However, the metabolic deactivation product of ABA, phaseic acid, exhibited an early peak on the first day in ‘Okanese’. Conclusions Our results indicate that PtCBFs and PtDAM1 have differential kinetics and spatial localization which may be related to early growth cessation and endodormancy induction under the regime of low night temperature and short photoperiod in poplar. Unlike buds, PtCBFs and PtDAM1 expression levels in leaves were not associated with early growth cessation and dormancy induction under these conditions. Our study provides new evidence that the degradation of auxin and cytokinins in leaves may be an important regulatory point in a CBF-DAM induced endodormancy. Further investigation of other PtDAMs in bud tissue and a study of both growth-inhibiting and the degradation of growth-promoting phytohormones is warranted.

Elucidation of molecular and hormonal background of early growth cessation and endodormancy induction in two contrasting Populus hybrid cultivars

Background Over the life cycle of perennial trees, the dormant state enables the avoidance of abiotic stress conditions. The growth cycle can be partitioned into induction, maintenance and release and is controlled by complex interactions between many endogenous and environmental factors. While phytohormones have long been linked with dormancy, there is increasing evidence of regulation by DAM and CBF genes. To reveal whether the expression kinetics of CBFs and their target PtDAM1 is related to growth cessation and endodormancy induction in Populus, two hybrid poplar cultivars were studied which had known differential responses to dormancy inducing conditions.Results Growth cessation, dormancy status and expression of six PtCBFs and PtDAM1 were analyzed. The ‘Okanese’ hybrid cultivar ceased growth rapidly, was able to reach endodormancy, and exhibited a significant increase of several PtCBF transcripts in the buds on the 10th day. The ‘Walker’ cultivar had delayed growth cessation, was unable to enter endodormancy, and showed much lower CBF expression in buds. Expression of PtDAM1 peaked on the 10th day only in the buds of ‘Okanese’. In addition, PtDAM1 was not expressed in the leaves of either cultivar while leaf CBFs expression pattern was several fold higher in ‘Walker’, peaking at day 1. Leaf phytohormones in both cultivars followed similar profiles during growth cessation but differentiated based on cytokinins which were largely reduced, while the Ox-IAA and iP7G increased in ‘Okanese’ compared to ‘Walker’. Surprisingly, ABA concentration was reduced in leaves of both cultivars. However, the metabolic deactivation product of ABA, phaseic acid, exhibited an early peak on the first day in ‘Okanese’.Conclusions Our results indicate that PtCBFs and PtDAM1 have differential kinetics and spatial localization which may be related to early growth cessation and endodormancy induction under the regime of low night temperature and short photoperiod in poplar. Unlike buds, PtCBFs and PtDAM1 expression levels in leaves were not associated with early growth cessation and dormancy induction under these conditions. Our study provides new evidence that the degradation of auxin and cytokinins in leaves may be an important regulatory point in a CBF-DAM induced endodormancy. Further investigation of other PtDAMs in bud tissue and a study of both growth-inhibiting and the degradation of growth-promoting phytohormones is warranted.

In vitro propagation of the genus Echinacea Moench representatives

The regenerative capacity of Echinacea hybrid cultivar Mama Mia and the selected somaclonal variegated variant at the propagation and rooting stages was compared. The influence of the 6-BAP concentration in the MS culture medium on the microrosette formation at the propagation stage was studied. The highest morphogenetic potential of the selected form in comparison with the cultivar Mama Mia was found. It was shown that ½ MS culture medium supplemented with 0.3 mg/L IAA was the optimal medium for effective development of the root system of the genus Echinacea representatives at the rooting stage.