Molecular and biochemical analysis of supplementation of calcium under in vitro condition on tuberization in potato ( Solanum tuberosum L.)

Calmodulin and calcium signaling in potato tuberization: The role of membrane transporters in stress adaptation

Potato tuberization is a complex developmental process influenced by environmental factors, such as light and temperature, as well as genetic and biochemical factors. Tuber formation is responsive to day length, with shorter days inducing tuberization more effectively than longer days. Potato tuber yield is regulated by signaling networks involving hormones, transcriptional regulators, and sugars. Calcium plays a pivotal role in this process. Elevated cytoplasmic calcium is detected by calcium sensors, including calmodulins (CaMs), calmodulin-like proteins (CMLs), Ca2+-dependent protein kinases (CDPKs), and calcineurin-B-like proteins (CBLs), promoting tuberization and growth. This review provides mechanistic insights into calcium signaling in potato tuberization, emphasizing its role in stress adaptation. This review further explores the role of calcium/calmodulin in stress response mechanisms and the membrane transporters that facilitate adaptation to environmental challenges like drought, cold, flooding, and heat stress, which are significant threats to potato production globally. Additionally, calcium signaling helps develop tolerance to both abiotic stresses and pathogens, ultimately enhancing plant immune responses to protect potato tubers.

Potato microtuberization: its regulation and applications

Potato (Solanum tuberosum L.) is a globally consumed staple food crop grown in temperate regions. The underground storage organs (tubers) are a rich source of carbohydrates, proteins, vitamins, and minerals, contributing to food and nutritional security. Tuberization, the process by which underground stems (stolons) develop into tubers, is intricately regulated by genetic, epigenetic, and environmental factors. Studying the developmental transition from stolon to tuber in soil-based systems is challenging due to the limited visibility of below-ground stages. Microtuberization is the formation of small tubers under controlled, soil-less, and in vitro conditions, offering an effective alternative for precise monitoring of tuber development stages. Microtubers are valuable as disease-free seed propagules and essential for germplasm conservation, supporting the preservation and propagation of genetic resources. Microtuberization is influenced by both internal factors, viz., genotype and explant, and external factors, viz., photoperiod, temperature, light, plant growth regulators, sucrose, and synthetic molecules. These factors collectively regulate the transition from stolon to tuber. Microtubers exhibit strong similarities to field-grown tubers, making them a reliable model to study the environmental and molecular mechanisms of tuberization. This review examines the key factors driving microtuberization and explores potential molecular regulators involved in stolon-to-tuber transition. Furthermore, the applications of microtuberization are highlighted, including disease-free seed production, mass multiplication, germplasm evaluation and conservation, molecular farming, genetic engineering, and stress adaptation research. Additionally, microtubers serve as an experimental tool for unraveling the molecular intricacies of tuberization, paving the way for advancements in potato research and global food security strategies.

A Model Nutrition Control System in Potato Tissue Culture and Its Influence on Plant Elemental Composition

Low or excessive soil fertility is a major constraint to potato production. The influence of each individual nutrient element on potato plants under field studies remains ambiguous due to the influence of environmental variations. Creating an in vitro model plant with deficient or excessive nutrient content will provide a more controlled study and allow for a better understanding of how the concentration of one element can affect the uptake of other elements. Here we designed a tissue culture-based nutrition control system to systematically analyze the effects of essential nutrients on potato plants. Insufficient or excessive nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) contents were created by modifying the Murashige and Skoog (MS) medium. Deficient to toxic plant nutrient statuses were successfully defined by the evaluation of dry biomass and morphological symptoms. The results showed that plant shoot growth, nutrient uptake and content, and nutrient interactions were all significantly impacted by the changes in the MS media nutrient concentrations. These tissue culture systems can be successfully used for further investigations of nutrient effects on potato production in response to biotic and abiotic stresses in vitro.