Consequences of drought stress in crop production systems are perhaps more deleterious than other abiotic stresses under changing climatic scenario. Regulations in physio-biochemical responses under drought stress are crafted in to agronomic traits by the plants that can be used as markers for drought stress tolerance from selection and breeding point of view. Present study was conducted to appraise the performance of three different maize hybrids i.e., Dong Dan 80, Wan Dan 13 and Run Nong 35 under well watered, low, moderate and severe drought conditions maintained at 100, 80, 60 and 40% field capacities, respectively. Compared with well-watered, drought stress exhilarated oxidative stress in terms of reactive oxygen species (ROS) production which led to reduced growth and yield formation in all maize hybrids; nevertheless negative effects were more prominent in Run Nong 35. Drought-induced osmolyte accumulation and strong enzymatic and non-enzymatic defense system prevented severe damages in Dong Dan 80. Furthermore, in most of the cases correlations of ROS, omolytes and anti-oxidant defense system were found negative with shoot dry weight (SDW), grain yield (GY) and biological yield (BY) under drought conditions. Overall performance of all maize hybrids under drought stress was recorded as: Dong Dan 80 > Wan Dan 13 > Run Nong 35 with 6.39, 7.35 and 16.55% yield reductions. Consequently, these biochemical traits and differential physiological responses might be helpful to develop drought tolerance genotypes that can withstand against water-deficit conditions with minimum yield losses.

Chlorophyll degradation and anthocyanin biosynthesis, which often occur almost synchronously during fruit ripening, are crucial for vibrant coloration of fruits. However, the interlink point between their regulatory pathways remains largely unknown. Here, two litchi (Litchi chinensis Sonn.) cultivars with distinctively different coloration patterns during ripening, i.e. slow-reddening/stay-green ‘Feizixiao’ (FZX) vs rapid-reddening/degreening ‘Nuomci’ (NMC), were selected as the materials to study the key factors determining coloration. L. chinensis STAY-GREEN (LcSGR) was confirmed as the critical gene in pericarp chlorophyll loss and chloroplast breakdown during fruit ripening, as LcSGR directly interacted with pheophorbide a oxygenase (PAO), a key enzyme in chlorophyll degradation via the PAO pathway. L. chinensis NAM (No apical meristem), ATAF1/2(Arabidopsis transcription activation factor 1/2) and CUC2 (cup-shaped cotyledon 2) (LcNAC002) was identified as a positive regulator in the coloration of litchi pericarp. The expression of LcNAC002 was significantly higher in NMC than in FZX. Virus induced gene silencing (VIGS) of LcNAC002 significantly decreased the expression of LcSGR as well as L. chinensis MYELOBLASTOSIS1 (LcMYB1), and inhibited chlorophyll loss and anthocyanin accumulation. A dual-luciferase reporter (DLR) assay revealed that LcNAC002 significantly activates the expression of both LcSGR and LcMYB1. Furthermore, yeast one-hybrid (Y1H) and electrophoretic mobility shift assay (EMSA) results showed that LcNAC002 directly binds to the promoters of LcSGR and LcMYB1. These findings suggest that LcNAC002 is an important ripening-related transcription factor that interlinks chlorophyll degradation and anthocyanin biosynthesis by co-activating the expression of both LcSGR and LcMYB1.

Plants produce an incredible variety of volatile organic compounds (VOCs) that assist the interactions with their environment, such as attracting pollinating insects and seed dispersers and defense against herbivores, pathogens, and parasites. Furthermore, VOCs have a significant economic impact on crop quality, as well as the beverage, food, perfume, cosmetics and pharmaceuticals industries. These VOCs are mainly classified as terpenoids, benzenoids/phenylpropanes, and fatty acid derivates. Fruits and vegetables are rich in minerals, vitamins, antioxidants, and dietary fiber, while aroma compounds play a major role in flavor and quality management of these horticultural commodities. Subtle shifts in aroma compounds can dramatically alter the flavor and texture of fruits and vegetables, altering their consumer appeal. Rapid innovations in -omics techniques have led to the isolation of genes encoding enzymes involved in the biosynthesis of several volatiles, which has aided to our comprehension of the regulatory molecular pathways involved in VOC production. The present review focuses on the significance of aroma volatiles to the flavor and aroma profile of horticultural crops and addresses the industrial applications of plant-derived volatile terpenoids, particularly in food and beverages, pharmaceuticals, cosmetics, and biofuel industries. Additionally, the methodological constraints and complexities that limit the transition from gene selection to host organisms and from laboratories to practical implementation are discussed, along with metabolic engineering’s potential for enhancing terpenoids volatile production at the industrial level.