Cytology of Potato Callus Cells in Relation to their Frost Hardiness

Structure of callus cells of frost-sensitive and frost-tolerant Solanum species and a frost-tolerant cell line (D20-1), selected from S. tuberosum cv. Desirée callus, was studied. Like frost-tolerant species S. commersonii, cells of the frost-tolerant cell line contained starch grains in their plastids. The cells of this frost-tolerant line also possessed an increased number of microbodies containing protein crystals which suggests the involvement of proteins in frost tolerance but the mechanism may differ from that in frost-tolerant species.     

Biochemical Changes in Tuber-bearing Solanum Species in Relation to Frost Hardiness during Cold Acclimation

Biochemical changes in potato leaves during cold acclimation have been examined and compared between a frost-tolerant S. acaule and a frost-susceptible S. tuberosum species. Changes were also examined in S. tuberosum, S. acaule, and S. commersonii species when they were hardened at different temperatures to varying hardiness levels.     

Induction of Frost Hardiness in Stem Cortical Tissues of Cornus stolonifera Michx. by Water Stress: II. Biochemical Changes

A decrease of protein, RNAs, and starch, and an increase of sugar were observed in 3-day water-stressed red osier dogwood plants (Cornus stolonifera Michx.) when the frost hardiness increased from −3 to −6 C. As the frost hardiness increased to −11 C after 7 days of treatment, the starch continuously decreased, however, the proteins and RNAs increased with a continuous increase of sugar. Further water stress treatment had little effect on the changes of these chemicals. Control plants in short days showed similar gradual biochemical changes in patterns. From the results of frost hardiness increases, the pattern of biochemical changes, and the mechanism of the increased freezing resistance, it appears that the water stress and short days accomplished essentially the same physiological end(s) in inducing frost hardiness in red-osier dogwood.     

Antimicrobial Activity and Mechanism of Essential Oil of Endemic Salvia hypargeia Finc. & Mey. in Turkey

In this study, the aerial parts of Salvia hypargeia were subjected to hydrodistillation and the resulting compounds were analyzed in GC–MS. Antimicrobial activity of S. hypargeia essential oil (EO) against A. baumannii, S. aureus, and C. tropicalis were determined by agar well diffusion assay and microdilution method. Antimicrobial mechanism of the EO were investigated based on change of TTC-dehydrogenase relative, leakages of intracellular protein, DNA and potassium ion (K +). The main components of the EO were β-pinene, 1,8-cineole, camphor, α-pinene, 4-terpineol, and 4-thujanol. The MICs of the EO against the microorganisms were 15.2 mg/mL for S. aureus, 17.5 mg/mL for C. tropicalis and 28.8 mg/mL for A. baumannii. The inhibition zones were 18.16 mm, 25.01 mm, and 27.01 mm for A. baumannii, S. aureus, and C. tropicalis, respectively (p < 0.05). An increase in DNA, protein and K⁺ leakage was observed when microorganisms were exposed to the EO. The TTC-DRA of the treated microorganism cells was also significantly decreased because of slowing the respiration. The present study provided an experimental basis of practical application of S. hypargeia EO as a natural agent.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12088-021-00939-1.     

Biological Conversion of Benzoic Acid in Lemna paucicostata 151 and its Relation to Flower Induction

Benzoic acid, known to induce flowering in Lemnaceae, was shownto be converted to four major compunds in Lemna paucicostata151. These compounds were isolated and determined to be N-benzoylaspartate, benzyl 6-O-ßdD-apiofuranosyl-ß-D-glucopyranoside,O-benzoyl isocitrate and O-benzoyl malate. (Received November 2, 1987; Accepted January 23, 1988)     

Gibberellins, Endogenous and Applied, in Relation to Flower Induction in the Long-Day Plant Lolium temulentum

Changes in endogenous gibberellin-like substances (GAs) and related compounds in the shoot apices of Lolium temulentum during and after flower induction by one long day was examined for plants grown in three consecutive years. The total GA level in the shoot apical tissue was high (up to 42 micrograms per gram dry weight, or 3 × 10⁻⁵ molar GA₃ equivalents), increasing several-fold on the day after the long day and then declining. Of the many GA-like substances present, the putative polyhydroxylated components—with HPLC retention times between those of GA₈ (three hydroxyls) and GA₃₂ (four hydroxyls), and accounting for about a quarter of the total GA activity—were most consistent and striking in their changes. Their level in the apices increased 3- to 5-fold on the day after the long day and then subsided. When various GAs were applied to plants in noninductive short days, flower initiation was induced by several, most notably by GA₃₂, GA₅, 2,2-dimethyl GA₄, GA₃, and GA₇. GA₃₂ was most like one long day in eliciting a strong flowering response while having little effect on stem growth, whereas GA₁ had the opposite effect. It is suggested that highly hydroxylated C-19 GAs may play a central role in the induction of flowering in this long-day plant.