Yield maintenance under drought is orchestrated by theqDTY12.1-encodedDECUSSATEgene of rice through a network with other flowering-associated genes across the genetic background

Abstract

Introgression of major-effect QTLs is an important component of rice breeding for yield-retention under drought. While largely effective, the maximum potentials of such QTLs have not been consistent across genetic backgrounds. We hypothesized that synergism or antagonism with additive-effect peripheral genes across the background could either enhance or undermine the QTL effects. To elucidate the molecular underpinnings of such interaction, we dissected qDTY12.1 synergy with numerous peripheral genes in context of network rewiring effects. By integrative transcriptome profiling and network modeling, we identified the DECUSSATE ( OsDEC ) within qDTY12.1 as the core of the synergy and shared by two sibling introgression lines in IR64 genetic background, i.e., LPB (low-yield penalty) and HPB (high-yield penalty). OsDEC is expressed in flag leaves and induced by progressive drought at booting stage in LPB but not in HPB. The unique OsDEC signature in LPB is coordinated with 35 upstream and downstream peripheral genes involved in floral development through the cytokinin signaling pathway, which are lacking in HPB. Results further support the differential network rewiring effects through genetic coupling-uncoupling between qDTY12.1 and other upstream and downstream peripheral genes across the distinct genetic backgrounds of LPB and HPB . We propose that the functional DEC -network in LPB defines a mechanism for early flowering as a means for avoiding the depletion of photosyntate needed for reproductive growth due to drought. Its impact on yield-retention is likely through the timely establishment of stronger source-sink dynamics that sustains a robust reproductive transition under drought.

Genomic regions and candidate genes affect root anatomical traits in diverse rice accessions

“…OsTDL1a and OsLGC1 were both annotated for cell fate determination, but their roles seem to be localized to reproductive tissues (Kusaba et al, 2003;Yang et al, 2016). OsDEC (Os12g0465700 ) plays a role in cytokinin signaling, phylotaxy, and reducing flowering delay under drought (Itoh et al, 2012;Sanchez et al, 2021), but its potential role in root anatomical development is not clear.…”