Plasticity of root growth and respiratory activity: Root responses to aboveground senescence, fruit removal or partial root pruning in soybean

FANELLO D.D; KELLY S.J.; BARTOLI C.G.; CANO M.G.; MARTÍNEZ ALONSO, S.M.; GUIAMET J.J.

PLANT SCIENCE

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2020 vol. 290

0168-9452

This work focuses on the alterations in soybean root growth and activity during whole plant senescence and thecontribution of roots to source-sink relations during plant development. The experiments were designed toanalyze the activity of roots in relation to: a) whole plant senescence, b) total pod removal and c) root pruning(15, 25 and 50% of DW) during seed growth stages. Roots can grow until an advanced R5 stage and their specificactivity decreases along the reproductive development but whole root activity declines from R6. However rootrespiration is maintained at a basal level until R8. Depodded plants showed a large increase of root dry matter(about 470%) and a large increase of AOX protein. Root pruning treatments showed a proportional increase ofspecific root respiration in 25 and 50% treatments but no differences of whole root respiration and dry matterpartitioning at R7. These results indicate that roots are under the control of the requirements of above groundorgans until final stages of seed growth but, after this, roots may survive independently for some time. Thissuggests that roots do not suffer a senescence-like process as leaves do. Also, plants have a high capacity to bufferchanges in root biomass production and specific root activity under pod removal or partial root pruning.