Abstract Detail

Physiology

Duran, Kristy [1], Shanks, Kevin [2], Ortega, Stefan [2], Duran, Cody [2].

Effects of nitrate on the root hydraulic conductivity in legumes with and without Rhizobium symbiosis.

Nitrogen is a limiting nutrient in plants that is essential for many cellular and molecular functions. Nitrogen is acquired from the roots of the plant as nitrate, and usually taken into the plant with water via aquaporins. Leguminous plants form an association with symbiotic bacteria that are able to fix nitrogen from the atmosphere and are housed within nodules formed on the host root. Previous studies show increased root hydraulic conductivity in response to high nitrogen in non-leguminous plants. This study examines effects of nitrate on root hydraulic conductivity in the legume, Phaseolus vulgaris, at two, four, and six-week seedling. We also examine whether the symbiotic relationship with Rhizobium affects these results. A split root experiment was used to examine the differential uptake of water in response to the addition of a high nitrate solution. Fifteen plants were inoculated with the Rhizobium and fifteen were not. Five plants of each treatment were grown for two weeks after germination and, five plants of each treatment were grown for four weeks, and five plants of each treatment were grown for six weeks in a low nitrate solution. Two-week seedlings from both inoculated and un-inoculated plants took up more of the low nitrogen solution. At four-weeks, the inoculated plants continued to take up the low nitrate solution, however, there was no difference in water uptake between low and high nitrate levels. At six weeks, the inoculated plants continued to take up the low nitrate solution, but the un-inoculated plants took up more of the high nitrate solution. These results may be explained by the symbiotic relationship between legumes and Rhizobium. Plants with Rhizobium may have a mechanism to limit the amout of water they acquire. On the other hand, legumes may have also mechanism that allows them to take up more water and therefore more nitrogen at later growth stages in response to high nitrogen when lacking the symbiotic relationship with Rhizobium.

1 - Adams State University, Biology and Earth Science, 208 Edgemont Blvd, Alamosa, Colorado, 81101, USA
2 - Adams State University, Biology and Earth Science

Keywords:
none specified

Presentation Type: Poster
Session: P, Physiological Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPS005
Abstract ID:739
Candidate for Awards:None