Ectopic expression of a pea apyrase enhances root system architecture and drought survival in Arabidopsis and soybean

Abstract

Ectoapyrases (ecto-NTPDases) function to decrease levels of extracellular ATP and ADP in animals and plants. Prior studies showed that ectopic expression of a pea ectoapyrase, psNTP9, enhanced growth in Arabidopsis seedlings and that the overexpression of the two Arabidopsis apyrases most closely related to psNTP9 enhanced auxin transport and growth in Arabidopsis. These results predicted that ectopic expression of psNTP9 could promote a more extensive root system architecture (RSA) in Arabidopsis. We confirmed that transgenic Arabidopsis seedlings had longer primary roots, more lateral roots, and more and longer root hairs than wild-type plants. Because RSA influences water uptake, we tested whether the transgenic plants could tolerate osmotic stress and water deprivation better than wild-type plants, and we confirmed these properties. Transcriptomic analyses revealed gene expression changes in the transgenic plants that helped account for their enhanced RSA and improved drought tolerance. The effects of psNTP9 were not restricted to Arabidopsis, because its expression in soybeans improved the RSA, growth, and seed yield of this crop and supported higher survival in response to drought. Our results indicate that in both Arabidopsis and soybeans, the constitutive expression of psNTP9 results in a more extensive RSA and improved survival in drought stress conditions.

Spatial regulation of thermomorphogenesis by HY5 and PIF4 in Arabidopsis

“…Root system architecture plays a crucial role in crop productivity 28,29,48 and high ambient temperature affects both primary and lateral root growth 26,27,30 . The phenotypic analyses show that seedlings display a general growth promotion including elongation of hypocotyls, petioles and roots, and thickening of hypocotyls in response to high ambient temperature.…”

“…High ambient temperature also affects root system architecture 26,27 , which is linked to crop yield 28,29 . In sunflower and cotton, elevated temperature increases lateral root length and number 27 .…”

Role of Ca2+ in Mediating Plant Responses to Extracellular ATP and ADP

“…The first ectoapyrase used in these transformation studies was psNTP9, which Thomas et al [ 92 ] showed could promote phosphate uptake and leaf growth when it was expressed in Arabidopsis seedlings. More recent studies, which examined the effects of ectopically expressing psNTP9 on mature plants, showed that it improved phosphate uptake, leaf growth, root-system architecture, and seed yield in both Arabidopsis and soybean plants [ 93 ]. Genetic manipulation of ectoapyrase expression in Arabidopsis has been carried out in numerous other studies.…”

“…Besides the report of Veerappa et al [ 93 ] noted above, several other transformation studies have been used to explore the function of apyrases in crop plants. The overexpression of an endogenous apyrase in Lotus japonicus [ 96 ] promoted nodulation, and the suppression of the GS52 apyrase in soybean inhibited nodulation [ 97 ].…”

Legumes—The art and science of environmentally sustainable agriculture

“…These authors consider the genomics approaches that have led to recent discoveries relating to adaptive genes in legumes. Individual mechanisms that allow survival of extremes of water availability are reported in several manuscripts.For example, the ectoapyrases, otherwise known as ecto-NTPDases that function to decrease levels of extracellular ATP and ADP are shown to be important in drought tolerance(Veerappa et al, 2018), as are the micro RNAs, miR398, and miR2119 in controlling superoxide dismutase and alcohol dehydrogenase mRNAs (De la Rosa,Covarrubus, & Reyes, 2018). The role of the alternative oxidase (AOX) in legumes in plant growth and performance is discussed in the paper bySweetman, Soole, Jenkins, and Day (2018).…”