Short-Term Post-Harvest Stress that Affects Profiles of Volatile Organic Compounds and Gene Expression in Rocket Salad during Early Post-Harvest Senescence

Abstract

Once harvested, leaves undergo a process of senescence which shares some features with developmental senescence. These include changes in gene expression, metabolites, and loss of photosynthetic capacity. Of particular interest in fresh produce are changes in nutrient content and the aroma, which is dependent on the profile of volatile organic compounds (VOCs). Leafy salads are subjected to multiple stresses during and shortly after harvest, including mechanical damage, storage or transport under different temperature regimes, and low light. These are thought to impact on later shelf life performance by altering the progress of post-harvest senescence. Short term stresses in the first 24 h after harvest were simulated in wild rocket (Diplotaxis tenuifolia). These included dark (ambient temperature), dark and wounding (ambient temperature), and storage at 4 °C in darkness. The effects of stresses were monitored immediately afterwards and after one week of storage at 10 °C. Expression changes in two NAC transcription factors (orthologues of ANAC059 and ANAC019), and a gene involved in isothiocyanate production (thiocyanate methyltransferase, TMT) were evident immediately after stress treatments with some expression changes persisting following storage. Vitamin C loss and microbial growth on leaves were also affected by stress treatments. VOC profiles were differentially affected by stress treatments and the storage period. Overall, short term post-harvest stresses affected multiple aspects of rocket leaf senescence during chilled storage even after a week. However, different stress combinations elicited different responses.

Volatile Profile of Wall Rocket Baby-Leaves (Diplotaxis erucoides) Grown under Greenhouse: Main Compounds and Genotype Diversity

“…By contrast, for mature leaves, stems and pods, Clemente-Villalba et al [33] only identified allyl ITC, 3-butenyl ITC and phenylethyl ITC. The presence and relative contribution of individual ITCs in wall rocket differs considerably to those reported in the rocket crops [11,22,26,29,[34][35][36][37][38][39][40]. Thus, three compounds identified in the present study for wall rocket (i.e., allyl ITC, benzyl ITC and phenylethyl ITC) were not reported in the literature for the related rocket crops (Table S1).…”

Reduced Fertilization to Improve Sustainable Use of Resources and Preserve Postharvest Quality of Fresh-Cut Wild Rocket (Diplotaxis tenuifolia L.) in Soil-Bound and Soilless Cultivation

“…In the experiments, six cuts occurred from mid-December to early May. Harvests were carried out when leaves of different treatments reached the commercial harvest stage (approximately until several serrated 10–12 cm leaves were present on each plant) [ 22 , 23 ]. Leaf samples were collected and weighed in order to determine yields and placed into a forced-draft oven at 65 °C to determine the dry matter percentage.…”

The Effect of Plant Growth Compensation by Adding Silicon-Containing Fertilizer under Light Stress Conditions

“…In each nest, five small depressions were made in which one seed of the red-or green-leaved lettuce (Lactuca sativa L.) was sown [38]. Such types of salad lettuces are commonly used to perform diverse studies on plant cultivation under different conditions [39][40][41][42], We experimented with two varieties of lettuce: the green-leaved lettuce called Azart (Prestizh Semena, www.pr-semena.ru, accessed on 1 May 2020, Russia), and the red-leaved lettuce called Robin (MoravoSeed, 1 May 2020, Czech Republic).…”