A significant increase in rhizosheath carboxylates and greater specific root length in response to terminal drought is associated with greater relative phosphorus acquisition in chickpea

• Published in: Plant and soil 2021-03, Vol.460 (1/2), p.51-68
• Main Authors: Sharma, Manish, Pang, Jiayin, Wen, Zhihui, De Borda, Axel, Kim, Hee Sun, Liu, Yifei, Lambers, Hans, Ryan, Megan H., Siddique, Kadambot H. M.
• Format: Article
• Language: English
• Subjects: Australia; Biomedical and Life Sciences; Carboxylates; Carboxylic acids; Chickpea; Chickpeas; Cultivars; Drought; Droughts; Ecology; Environmental aspects; genotype; Genotypes; Greenhouses; Life Sciences; Phosphorus; Phosphorus in the body; Physiological aspects; Plant breeding; Plant growth; Plant Physiology; Plant Sciences; Regular Article; REGULAR ARTICLES; root growth; Roots (Botany); sand; soil; Soil mixtures; Soil Science & Conservation; Stomata; Water shortages; Water stress; Water use; water use efficiency
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-020-04776-x

Aims We investigated the effects of water stress under low phosphorus (P) supply on P-acquisition by chickpea, and identified a genotype with faster relative growth and P-acquisition rates. Methods We grew four genotypes in pots filled with a sand and soil mixture with a low P availability in a glasshouse. Plants were either well-watered or water-stressed, imposed at the reproductive stage. Plants were harvested when water-stressed plants fully closed their stomata. Results For all four genotypes, water stress reduced shoot and root growth, root mass ratio, and shoot P content, while it increased specific root length (except in ICC 456), water-use efficiency and the amount of rhizosheath carboxylates per gram root dry weight. A faster relative shoot P-acquisition rate in ICC 2884 was associated with a greater specific root length, a smaller mean root diameter and a greater increase in the amount of rhizosheath carboxylates in response to water stress under low P supply. Interestingly, under water stress ICC 2884 also maintained a similar physiological P-use efficiency to that of the well-watered plants. Conclusions ICC 2884 is recommended as a parental genotype in chickpea breeding programs to develop cultivars for low-P and terminal drought environments.