The Responses of Arterial Stiffness Parameter Beta-Derived Index of the Aorta and Illiac-Femoral Artery to Acute Hypovolemia in Rabbits.

Introduction: Acute hemorrhage decreases blood pressure (BP) and sometimes causes hypovolemic shock. At this time, peripheral arteries are supposed to contract and increase peripheral vascular resistance to raise BP. However, there has not been an adequate index of a degree of arterial stiffness. We assessed changes in arterial stiffness during rapid bleeding using new BP-independent vascular indices, aBeta and ifBeta, determined by applying the cardio-ankle vascular index theory to the elastic (aorta) and muscular (common iliac-femoral) arteries, respectively, in rabbits. Methods: Eleven Japanese white male rabbits were fixed at the supine position under pentobarbital anesthesia. Fifteen percent of the total blood volume was depleted at a rate of 2 mL/kg/min for 6 min; 15 min later, the withdrawn blood was re-transfused at the same rate. Pressure waves at the origin of the aorta (oA), distal end of the abdominal aorta (dA), distal end of the left common iliac artery (fA), and flow waves at oA were measured simultaneously. Beta was calculated using the following formula: beta = 2ρ/PP × ln(SBP/DBP) × PWV2, where ρ, SBP, DBP, and PP are blood density, systolic, diastolic, and pulse pressures, respectively. aBeta, ifBeta, and aortic-iliac-femoral beta (aifBeta) were calculated using aPWV, ifPWV, and aifPWV, respectively. Results: BP declined significantly at oA, dA, and fA during the acute bleeding. aBeta and aifBeta increased significantly from 3.7 and 5.0 before the bleeding (control) to 5.0 (about 34%) and 6.3 (about 26%) on average, while ifBeta decreased significantly from 20.5 before the bleeding to 17.1 (about 17%) after the completion of the bleeding. Reverse reactions of those indices were observed by transfusing the removed blood. Conclusion: Total arterial stiffness (aifBeta) increased; however, the elastic and muscular arteries stiffened and softened during the bleeding, respectively. These results would give useful diagnostic information during fall in BP.

Non-thermal atmospheric-pressure plasma exposure as a practical method for improvement of Brassica juncea seed germination.

Here we report that non-thermal atmospheric-pressure plasma exposure can improve Brassica juncea (leaf mustard) seed germination rate from 50 % to 98 %. The commercially relevant germination rate was achieved by plasma exposure for only 10 minutes and the effect sustains at least for one month under an appropriate storage condition. Improved germination by plasma exposure was also observed for Brassica rapa subsp. pekinensis (Chinese cabbage) seeds. The plasma device used is simple. No pure gas flow system is necessary and it is easy to handle. A large number of seeds can be treated by simply scaling up the device. Plasma exposure can be a practical method for improving seed germination of crop plants important for agriculture.

Petal abscission is promoted by jasmonic acid-induced autophagy at Arabidopsis petal bases.

In angiosperms, the transition from floral-organ maintenance to abscission determines reproductive success and seed dispersion. For petal abscission, cell-fate decisions specifically at the petal-cell base are more important than organ-level senescence or cell death in petals. However, how this transition is regulated remains unclear. Here, we identify a jasmonic acid (JA)-regulated chromatin-state switch at the base of Arabidopsis petals that directs local cell-fate determination via autophagy. During petal maintenance, co-repressors of JA signaling accumulate at the base of petals to block MYC activity, leading to lower levels of ROS. JA acts as an airborne signaling molecule transmitted from stamens to petals, accumulating primarily in petal bases to trigger chromatin remodeling. This allows MYC transcription factors to promote chromatin accessibility for downstream targets, including NAC DOMAIN-CONTAINING PROTEIN102 (ANAC102). ANAC102 accumulates specifically at the petal base prior to abscission and triggers ROS accumulation and cell death via AUTOPHAGY-RELATED GENEs induction. Developmentally induced autophagy at the petal base causes maturation, vacuolar delivery, and breakdown of autophagosomes for terminal cell differentiation. Dynamic changes in vesicles and cytoplasmic components in the vacuole occur in many plants, suggesting JA-NAC-mediated local cell-fate determination by autophagy may be conserved in angiosperms.