Salt-tolerant crops show higher capacity for carbon fixation

Dec 12, 2011

Salt can have drastic effects on the growth and yield of horticultural crops; studies have estimated that salinity renders an about one-third of the world's irrigated land unsuitable for crop production. Imbalances in soil salinity can cause ion toxicity, osmotic stress, mineral deficiencies, and drastic physiological and biochemical changes in plants. Salt stress can even cause plants to adjust their water usage—to conserve water, some plants close their stomata, thus restricting the entry of carbon dioxide (CO2) into the leaf and reducing photosynthesis.

One solution to salinity issues has been to boost the salt tolerance of conventional crops and plants, but resulting gain in crop yield has traditionally been low. To better understand the behavior of salt-tolerant and -sensitive plants in challenging situations, scientists performed a comparative study of carbon fixation by different plant species under conditions of salinity. Tomato, lettuce, pepper, melon, and watermelon were tested in a greenhouse in southeast Spain. The net photosynthetic rate, gS, and transpiration rate of the plants were measured at atmospheric CO2 during the daytime and were related to the total chlorophyll, carbon, and mineral contents of each species.

According to the research study (HortScience), melon or pepper crops showed significantly lower photosynthetic rates when they were grown in saline conditions. The total chlorophyll content and carbon percentage were also lower in the salinity-treated plants of melon and pepper. Treated lettuce plants showed a significant decrease in photosynthetic rates and chlorophyll content, but there were no differences in carbon content. "On the other hand, there were no significant differences in the values of total chlorophyll content, photosynthetic rate, or carbon content for tomato and watermelon plants when control and salt-treated plants were compared", the report said. The mineral composition data showed greater increases of sodium in both roots and leaves of melon and pepper when were treated with NaCl compared with the rest of the species.

"Almost all of the results obtained showed that lettuce, pepper, and melon are less adapted to saline conditions and that these crops seem to be less efficient in CO2 fixation and, therefore, have less capacity for carbon accumulation", noted corresponding author Micaela Carvajal. "We concluded that the species more tolerant of saline conditions (tomato and watermelon) showed a higher capacity for fixation of atmospheric CO2 than the sensitive species (lettuce, melon, and pepper). These results seem to be related to the capacity of each species to maintain the photosynthetic processes and gS in stressing situations."

Explore further: Study shows how epigenetic memory is passed across generations

More information: The complete study and abstract are available on the ASHS HortScience electronic journal web site: hortsci.ashspublications.org/c… /abstract/45/12/1798

Provided by American Society for Horticultural Science

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Can bedding plants thrive with recyled water?

Dec 30, 2010

To conserve dwindling water resources, municipalities are encouraging the use of "recycled water", municipal wastewater that has been extensively treated and deemed safe to reuse for irrigation and other purposes. Using recycled ...

Early suntan helps lettuce crops

Aug 08, 2011

New Zealand’s intense ultraviolet light may be bad for the skin, but it could provide a boost for vegetable production, according to new research by a Massey University crop scientist.

Vermicompost beneficial for organically grown tomatoes

Nov 17, 2011

A study evaluated the effects of adding vermicompost to substrates in organically grown greenhouse tomatoes. Results showed the incorporation of vermicompost into organic substrates to be beneficial in terms of growth and ...

Plants can adapt genetically to survive harsh environments

Jan 31, 2011

A Purdue University scientist has found genetic evidence of how some plants adapt to live in unfavorable conditions, a finding he believes could one day be used to help food crops survive in new or changing environments.

How did flowering plants evolve to dominate Earth?

Dec 01, 2009

To Charles Darwin it was an 'abominable mystery' and it is a question which has continued to vex evolutionists to this day: when did flowering plants evolve and how did they come to dominate plant life on earth? Today a study ...

Recommended for you

For legume plants, a new route from shoot to root

13 hours ago

A new study shows that legume plants regulate their symbiotic relationship with soil bacteria by using cytokinins—signaling molecules— that are transmitted through the plant structure from leaves into ...

Controlling the transition between generations

Sep 18, 2014

Rafal Ciosk and his group at the FMI have identified an important regulator of the transition from germ cell to embryonic cell. LIN-41 prevents the premature onset of embryonic transcription in oocytes poised ...

User comments : 0