Short-term high temperature growth conditions during vegetative-to-reproductive phase transition irreversibly compromise cell wall invertase-mediated sucrose catalysis and microspore meiosis in grain sorghum (Sorghum bicolor).
Grain sorghum (Sorghum bicolor) crop yield is significantly compromised by high temperature stress-induced male sterility, and is attributed to reduced cell wall invertase (CWI)-mediated sucrose hydrolysis in microspores and anthers leading to altered carbohydrate metabolism and starch deficiency in pollen (Jain et al., 2007). Sorghum plants were grown under season-long ambient (30/20 degrees C day-time maximum/night-time minimum) or high temperature stress (HS, 36/26 degrees C) environments, or reciprocally transferred for 5-10 days between either temperature regimens through panicle and microspore developmental stages. Quantitative RT-PCR analyses for CWI gene SbIncw1, plasma membrane H(+)-ATPase (Mha1) and sugar transporter proteins (OsSUT3 and OsMST7 homologs in sorghum), starch deficiency and pollen sterility data are presented to confirm HS-sensitivity of pre- and post-meiotic stages of sorghum microsporogenesis. Heat stress-induced reduction in Incw transcriptional activity during microspore meiosis was irreversible despite return of optimal growth temperature conditions through further reproductive development.
Jain
Mukesh
M
Agronomy Department, University of Florida, Gainesville, FL 32611-0680, USA. mjain@ufl.edu
Chourey
Prem S
PS
Boote
Kenneth J
KJ
Allen
Leon H
LH
D018533:Biomass; D006358:Hot Temperature; D008540:Meiosis; D011058:Pollen / Q000254:growth & development*; D045868:Sorghum / Q000201:enzymology* / Q000254:growth & development; D013213:Starch / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*; D043324:beta-Fructofuranosidase / Q000378:metabolism*
D013395:Sucrose; D013213:Starch; D043324:beta-Fructofuranosidase