Involvement of abscisic acid and other stress indicators in taro (Colocasia esculenta (L.) Schott) response to drought conditions

• Published in: Acta physiologiae plantarum Vol. 42; no. 12
• Main Authors: Gouveia, Carla S. S., Ganança, José F. T., Slaski, Jan J., Lebot, Vincent, Pinheiro de Carvalho, Miguel Â. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2020; Springer Nature B.V
• Subjects: Abscisic acid; Agriculture; Biomedical and Life Sciences; Breeding; Chlorophyll; Climate change; Colocasia esculenta; Corms; Drought; Food; Food security; Life Sciences; Original Article; Oxalic acid; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Shoots; Stomata; Stress; Taro; Transpiration; Tropical environment; Tropical environments; Water loss; Water scarcity; Water use; Water use efficiency; Drought stress; Chlorophyll content index; Water use efficiency; Oxalic acid; Carbon isotope; Enzyme-linked immunosorbent assay
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-020-03162-5

Taro ( Colocasia esculenta (L.) Schott) is a staple food and represents an important food security role in most tropical regions. It is, unfortunately, susceptible to prolonged drought conditions. Abscisic acid (ABA) is a well-documented stress-induced phytohormone that tolerant crops usually accumulate in leaves to induce stomatal closure, preventing water loss through inhibition of transpiration. Hitherto, exists very scarce information regarding the ABA role in taro response to drought. Here, we determined the ABA content in the shoots and corms of taro subjected to seven months of water scarcity and linked ABA to other drought resilience traits, including carbon isotopic discrimination (Δ 13 C), oxalic acid (OA), chlorophyll content index (CCI), water use efficiency (WUE), and biomass (B). The Δ 13 C-shoot content showed partially open stomata in all accessions, and significant correlation with Δ 13 C-corm, CCI, and WUE. The osmotically active OA-shoot decrease seemed not to interfere with the stomatal aperture. The tolerant accessions subjected to drought stress had higher B-corm, ABA-shoot, Δ 13 C-shoot, CCI, OA, and WUE. However, the observed under drought conditions increase of ABA in the shoots, and its decrease in the corms were not significantly correlated, nor with other traits, suggesting that ABA was not the main regulator of taro physiological processes under stress. The information gained should be considered in breeding programs to predict taro’s response to climate change.