Blueberry, hailed as an antioxidant superfood, is the fruit of small shrubs in the genus Vaccinium (family Ericaceae). The fruits are a rich source of vitamins, minerals and antioxidants such as flavonoids and phenolic acids. The antioxidative and anti-inflammatory activities derived from the polyphenolic compounds, particularly from the abundantly present anthocyanin pigment, have been highlighted as the major contributing factor to the health-benefitting properties of blueberry. In recent years, blueberry cultivation under polytunnels has expanded, with plastic covers designed to offer protection of crop and fruit yield from suboptimal environmental conditions and birds. An important consideration is that the covers reduce photosynthetically active radiation (PAR) and filter out ultraviolet (UV) radiation that is critical for the fruit’s bioactive composition. Blueberry fruits grown under covers have been reported to have reduced antioxidant capacity as compared to fruits from open fields. In addition to light, abiotic stresses such as salinity, water deficit, and low temperature trigger accumulation of antioxidants. We highlight in this review how interventions such as light-emitting diodes (LEDs), photo-selective films, and exposure of plants to mild stresses, alongside developing new varieties with desired traits, could be used to optimise the nutritional quality, particularly the content of polyphenols, of blueberry grown under covers.

Indian sandalwood (Santalum album L.) is an expensive wood that requires reproducible method for mass propagation to ensure consistent production and sustainable use of sandalwood. For mass propagation of sandalwood, plant organogenesis requires different combinations of the tissue culture medium. The media is composed of exogenous phytohormones which decides the explant's morphological stages such as shooting or rooting induction. Early prediction of morphological stage from explant can potentially help in selecting the exogenous phytohormones combinations thereby saving time and resources for mass sandalwood propogation. An efficient protocol for the direct and indirect organogenesis (up to shooting development phase) of sandalwood were developed using Woody Plant Media (WPM). WPM supplemented with various concentrations of 6-Bezylaminopurine (BAP) and 1-Naphthaleneacetic acid (NAA) were tested for direct organogenesis, while different treatments consisting of various levels of 2,4-dichlorophenoxyacetic acid (2,4-D), NAA, BAP, Adenine sulphate (ADS), glycine and potassium nitrate were tested for indirect organogenesis. Three stages of leaf development were selected viz., the leaf just after inoculation in WPM media, initial stage of callus formation from leaf and shoot formation for expression pattern analysis. The targeted genes were Alternative oxidase (ao), Late embryogenesis abundant (lea), Cytochrome P450 (cyt-p450), ABC transporter (abct), and Serine-threonine phosphatase (stp) which are associated with in vitro organogenesis. The expression patterns were evaluated to identify a transcription marker. During the initial stages of organogenesis, ao, cyt-p450 and abct showed no/little change in expression in the direct pathway but up-regulation of ao and abct and downregulation of cyt-p450 were observed in the indirect pathway. Expression of lea was increased up to 70-fold during direct and dropped to half during indirect organogenesis.

Indian sandalwood (Santalum album L.) is an expensive wood that requires reproducible method for mass propagation to ensure sustainable use. Organogenesis employs different combinations of the medium;. its suitability is decided based on the explant’s morphological changes. Early prediction of organogenesis in the explant helps reduce the combinations thereby saving time and resources. We initially developed an efficient protocol for the direct and indirect organogenesis (up to shooting development phase) of sandalwood in the present investigation. Woody Plant Media (WPM) supplemented with various concentrations of 6-Bezylaminopurine (BAP) and 1-Naphthaleneacetic acid (NAA) were tested for direct organogenesis, while different treatments consisting of various levels of 2,4-dichlorophenoxyacetic acid (2,4-D), NAA, BAP, Adenine sulphate (ADS), glycine and potassium nitrate were tested for indirect organogenesis.Three stages of leaf development were selected viz., the leaf just after inoculation in WPM media, initial stage of callus formation from leaf and shoot formation for expression pattern analysis. The targeted genes were Alternative oxidase (ao), Late embryogenesis abundant (lea), Cytochrome P450 (cyt-p450), ABC transporter (abct), and Serine-threonine phosphatase (stp) which are associated with in vitro organogenesis. The expression patterns were evaluated to identify a transcription marker. During the initial stages of organogenesis, ao, cyt-p450 and abct showed no/little change in expression in thedirect pathway but up-regulation of ao and abct and downregulation of cyt-p450 were observed in the indirect pathway. Expression of lea was increased up to 70-fold during direct and dropped to half during indirect organogenesis.

The world's most expensive wood, sandalwood (Santalum album L.), requires a stringent mass-propagation technique to prevent future scarcity. Plant tissue culture is an efficient method that regenerates the whole plant from a single cell on a hormone-based growth medium. To efficiently regulate the formation of plants, it is important to understand the developmental organogenesis pathways (i.e., direct and indirect) through gene expression studies. Therefore, an effective protocol for the direct and indirect organogenesis of sandalwood was developed, followed by the characterization of gene expression patterns in investigation. Five in vitro organogenesis genes namely, Alternative oxidase (ao), Late embryogenesis abundant (lea), Cytochrome p450 (cyt-p450), ABC transporter (abct), and Serine-threonine phosphatase (stp), were screened from three stages of sandalwood development; (1) inoculated leaf, (2) proliferated leaf shoot/callus formation and (3) shoot formation. The best treatments for plant regeneration in Woody Plant Media (WPM) were SI24 (2.5 mg/l 2,4-D) for indirect organogenesis and SD14 (2.0 mg/l BAP and 0.4 mg/l-1 NAA) for direct organogenesis. During the initial stages of organogenesis, ao, cyt-p450 and abct showed no/little change in expression in the direct pathway however up-regulation of ao and abct and downregulation of cyt-p450 were observed in the indirect pathway. Expression of lea was increased up to 70-fold during direct and dropped to half during indirect organogenesis. The optimization of the sandalwood organogenesis regeneration medium and the identification of distinct gene expression patterns will serve as transcriptional markers for the early prediction of the organogenesis stage, assisting in the sandalwood conservation. Plant Tissue Cult. & Biotech. 32(2): 103-113, 2022 (December)