Abstract:
Climate change is causing droughts affecting crop production on a global scale. Classical
breeding and selection strategies for drought-tolerant cultivars will help prevent crop losses.
Plant breeders, for all crops, need a simple and reliable method to identify drought-tolerant
cultivars, but such a method is missing. Plant metabolism is often disrupted by abiotic stress
conditions. To survive drought, plants reconfigure their metabolic pathways. Studies have
documented the importance of metabolic regulation, i.e. osmolyte accumulation such as
polyols and sugars (mannitol, sorbitol); amino acids (proline) during drought. This study
identified and quantified metabolites in drought tolerant and drought susceptible Camellia
sinensis cultivars under wet and drought stress conditions. For analyses, GC-MS and LC-MS
were employed for metabolomics analysis. %RWC results show how the two drought tolerant
and two drought susceptible cultivars differed significantly (p ≤ 0.05) from one another; the
drought susceptible exhibited rapid water loss compared to the drought tolerant. There was a
significant variation (p < 0.05) in metabolite content (amino acid, sugars) between drought
tolerant and drought susceptible tea cultivars after short-time withering conditions. These
metabolite changes were similar to those seen in other plant species under drought conditions,
thus validating this method. The Short-time Withering Assessment of Probability for Drought
Tolerance (SWAPDT) method presented here provides an easy method to identify drought
tolerant tea cultivars that will mitigate the effects of drought due to climate change on crop
losses.
