Total FLC transcript dynamics from divergent paralogue expression explains flowering diversity in Brassica napus

Abstract

Summary Flowering time is a key adaptive and agronomic trait. In Arabidopsis, natural variation in expression levels of the floral repressor FLOWERING LOCUS C (FLC) leads to differences in vernalization. In Brassica napus there are nine copies of FLC. Here, we study how these multiple FLC paralogues determine vernalization requirement as a system. We collected transcriptome time series for Brassica napus spring, winter, semi‐winter, and Siberian kale crop types. Modelling was used to link FLC expression dynamics to floral response following vernalization. We show that relaxed selection pressure has allowed expression of FLC paralogues to diverge, resulting in variation of FLC expression during cold treatment between paralogues and accessions. We find that total FLC expression dynamics best explains differences in cold requirement between cultivars, rather than expression of specific FLC paralogues. The combination of multiple FLC paralogues with different expression dynamics leads to rich behaviour in response to cold and a wide range of vernalization requirements in B. napus. We find evidence for different strategies to determine the response to cold in existing winter rapeseed accessions.

Non-vernalization requirement in Chinese kale caused by loss of BoFLC and low expressions of its paralogs

“…Total expression of all the BnaFLC paralogs rather than the expression of individual BnaFLC paralogs determine vernalization requirement in B. napus (Calderwood et al 2021). In the current study, we discovered that the expression of BoFLC was much higher than that of its paralogs in B. oleracea.…”

Bootstrapping and Pinning down the Root Meristem; the Auxin–PLT–ARR Network Unites Robustness and Sensitivity in Meristem Growth Control

“…This combination of all-or-nothing and graded behavior, with the all-or-nothing behavior relying on positive feedback and the gradedness on the spatially or temporally graded nature of recruiting localized positive feedback, has been observed in multiple biological systems. Examples are the calcium-induced calcium release in cardiac muscle cells which amplitude governs muscle contraction strength [ 36 , 37 ] and the plant vernalization pathway that enables plants to determine whether a prolonged period of cold has passed and subsequent increases in temperature are hence indicative of spring [ 38 ]. In calcium-induced calcium release, the opening of individual endoplasmic reticulum calcium channels displays all-or-nothing behavior in response to local calcium levels while the number of channels recruited to open depends in a graded fashion on the total cellular calcium current [ 36 , 37 ].…”

“…In calcium-induced calcium release, the opening of individual endoplasmic reticulum calcium channels displays all-or-nothing behavior in response to local calcium levels while the number of channels recruited to open depends in a graded fashion on the total cellular calcium current [ 36 , 37 ]. Similarly, in vernalization, individual cells switch their epigenetic state to memorize their exposure to cold in an all-or-nothing non-reversible manner, yet since this switching is probabilistic the number of cells depends in a graded manner on the duration of the cold period [ 38 ].…”

ФАКТОРЫ ТРАНСКРИПЦИИ СЕМЕЙСТВА MADS РАСТЕНИЙ: СВЯЗЬ С ПРИЗНАКАМИ ДОМЕСТИКАЦИИ И ПЕРСПЕКТИВЫ ДЛЯ СЕЛЕКЦИИ (Обзор)

“…Яркий пример важности генов FLC -виды рода Brassica L. (семейство Brassicaceae -Капустные) (57). Так, раннее цветение у китайской капусты Brassica rapa ssp.…”