Transgenic Turfgrasses Expressing Hyperactive Ser599Ala Phytochrome A Mutant Exhibit Abiotic Stress Tolerance

Abstract

Turfgrasses are environmentally and recreationally valuable plants that are constantly subjected to various forms of stress in their artificial and natural habitats. Previously, it was shown that the transformation of a hyperactive mutant (Serine 599 Alanine, S599A) of oat phytochrome A in zoysia grass (Zoysia japonica) and creeping bentgrass (Agrostis stolonifera L.) resulted in superior quality turfgrass with improved shade tolerance response. We now examined the abiotic stress response of the transgenic turfgrasses expressing the hyperactive mutant S599A-PhyA. The transgenic S599A-PhyA plants subjected to high salinity and heavy metal toxicity stress exhibited higher chlorophyll content, lower hydrogen peroxide level, and higher proline accumulation than the controls. Furthermore, the anti-oxidative activities of four reactive oxygen species scavenging enzymes and the total biomass (above and below-ground) were higher in S599A-PhyA plants than in the controls under both the stress conditions. Moreover, higher photosynthetic efficiency (F v / F m ) of S599A-PhyA plants indicated healthier growth than the controls under stress conditions. Results suggest that the hyperactive mutant of oat phytochrome A confers abiotic stress tolerance in plants, and can be used to efficiently develop abiotic stress tolerant crops in future.

Melatonin Positively Influences the Photosynthetic Machinery and Antioxidant System of Avena sativa during Salinity Stress

“…Damage to PSII reaction centers (RCs) can be assessed by measuring maximal photochemical efficiency (Fv/Fm), which indicates a plant's ability to grow under unfavorable environmental conditions [25]. The NaCl and Mel+NaCl groups had remarkably lower Fv/Fm ratios than the WW and Mel+W groups.…”

“…The leaf pieces were incubated in a plant growth chamber under a 16 h photoperiod at a light intensity of 100 µM m −2 s −1 at 25 ± 1 • C until visual differences in greenness were observed between groups. The picture was taken after 3 days of experiment and then the chlorophyll content of the pieces was measured, as previously described [25].…”

Development of transgenic crops based on photo‐biotechnology

“…), tolerances to abiotic stresses such as cold, salt and heavy metals (Gururani et al . , ), and biomass production (Heyer et al . ; Thiele et al .…”

“…Through genetic transformation of crop plants with photoreceptors, it has been possible to develop the plants with enhanced yields and improved commercial benefits [e.g. seed productivity or harvest index (Holefors et al 1998;Kong et al 2004;Ganesan et al 2012), tolerances to abiotic stresses such as cold, salt and heavy metals (Gururani et al 2015b(Gururani et al , 2016, and biomass production (Heyer et al 1995;Thiele et al 1999;Rao et al 2013)], which will be discussed in this review. Moreover, several schematic and photographic illustrations have been included throughout the review primarily for the student readers.…”

Current Understanding of the Interplay between Phytohormones and Photosynthesis under Environmental Stress

“…A series of mathematical calculations is then used to simplify this information via specialized software. Because it is a simple method and gives detailed information on plants’ photosynthetic components under various stress conditions, OJIP analysis has gained wide acceptance over the past few years [ 15 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ].…”