The Effect of Drought on Lignin Content and Digestibility of Tifton-85 and Coastal Bermudagrass (<i>Cynodon dactylon</i> L.) Hays Produced in Georgia

Abstract

Digestibility of "Tifton 85" Bermudagrass has been noted to be higher than most other Bermudagrass cultivars. However, the superior digestibility of Tifton-85 has not been verified based on samples from producers, nor is it known how water availability might affect this comparison. Recent past weather conditions in Georgia allowed this comparison. Much of Georgia was in severe drought in 2007 and 2008. In contrast, there was less/no drought in 2006 and 2009. In each of these years, producers submitted a substantial number of Tifton-85 and Coastal forage samples to our laboratory for lignin and "Digestible Neutral Detergent Fiber (dNDF48)" analyses. Over all years, Tifton-85 had lower lignin content than coastal. However, Tifton-85 had significantly lower lignin content only in drought free 2006 and 2009, whereas the lignin content of Coastal was unaffected by drought in 2007 and 2008. The lignin of Tifton-85 increased during these two drought years. Despite this, the dNDF48 for Tifton-85 was significantly higher than coastal in all four years, suggesting that drought had hardly any effect on the digestibility of Tifton-85. Apparently, the type of lignin in Tifton-85 is different from that in coastal. Higher dNDF48 for Tifton-85 has been attributed to its lower concentrations of ether-linked ferulic acid than in Coastal. Decreased ether bonding in lignin results in higher digestion.

Arabidopsis CCoAOMT1 Plays a Role in Drought Stress Response via ROS- and ABA-Dependent Manners

“…It is well-known that plant cells change cell wall composition to adapt to abiotic stresses, such as salt and drought stress [ 38 ]. The study using bermudagrass Tifton-85 showed that the lignin content was increased under drought conditions [ 39 ], and greater lignin content in the xylem improves resistance to drought stress due to cell wall deposition [ 38 , 40 ]. Although the molecular mechanism for changes in cell wall dynamics by salt or drought stresses is unclear, the chemical reaction requires ROS to crosslink with phenolics [ 38 ].…”

The Impact of Drought in Plant Metabolism: How to Exploit Tolerance Mechanisms to Increase Crop Production

“…Under mild and mild/severe drought, the content of oleanolic acid and betulin increased in Betula platyphylla [96] and level of triterpenoid glycyrrhizin in Glycyrrhiza glabra [97]. The lignin content was increased in bermudagrass Tifton-85, which is a variety of Cynodon dactylon L., under drought conditions [98]. The flavonoids content was enhanced under stress conditions and high-water deficit conditions improved the medicinal properties of Labisia pumila [99].…”